Dena Cook and the Story Before the Headline

When Dena Cook joined Mattel in March 2019, the new job came with an unusually personal inventory. Barbie. Fisher-Price. Hot Wheels. These were brands from her childhood, and now from her son's. A corporate announcement had briefly turned into a family album. For a communications executive, it was a useful reminder: a company can occupy a place in someone's life long before anyone reads its strategy.

Cook arrived from Brew, where she had been CEO. Her assignment at Mattel covered communications inside and outside the company, around the world. The toy maker was developing its entertainment ambitions, including film projects involving Barbie and Hot Wheels. She would report directly to chairman and CEO Ynon Kreiz. The audience was larger than the business pages; the story had to make sense to employees, investors and people with a toy box.

Today, Cook is co-founder and CEO of Signal, a strategic communications firm established in 2023. Between those two roles sits a career spent close to company leaders, at moments when explaining a business becomes part of running it. The toys make a memorable entrance. The more revealing detail is where her desk sits in relation to the decisions.

The business before the headline

Before Brew and Mattel, Cook worked at Fleishman-Hillard and became a senior vice president at Zeno Group. Across her career, her client experience included Nintendo, PlayStation, Sirius Satellite Radio and Zynga. Even that short selection travels through several versions of modern entertainment: consoles, subscription audio and social games. The products changed. So did the way people encountered them.

Those names also suggest the limits of treating technology communications as a succession of launches. A console has players, developers, retailers and a parent considering the price. A new media business has to explain why someone should change an established habit. A launch can attract attention on Tuesday. The company still needs people to understand it on Wednesday.

Cook has described the principle that guided her early career: “PR should never be done in a vacuum.” She tied communications to a business objective. That is a practical test for a profession that can accumulate impressive-looking evidence of activity. A pile of coverage tells you something happened. It takes a further question to establish whether it helped.

Her own example was a year-long reputation program that improved a company's external relationships and produced benefits internally. She did not name the company. The choice of example is telling all the same: she reached for sustained work with consequences on both sides of the office door.

“PR should never be done in a vacuum.”

Dena Cook / 2019

A partnership with two coastlines

At Brew, Cook's working partnership with founder Brooke Hammerling joined Los Angeles and New York. By 2011, the agency was advising technology companies whose names were starting to appear in acquisition announcements and funding news. Its client roster included GroupMe and General Assembly. The geography mattered: these were businesses connecting software, media, money and audiences, with Cook operating from Los Angeles.

The partnership had come out of the agency world. Hammerling and Cook had both worked at Zeno. Cook became Brew's CEO, while Hammerling remained its founder. It is worth keeping the titles straight. An agency's reputation may attach itself to a conspicuous founder, but running the firm is a substantial job of its own: clients, colleagues, judgment and the obligation to keep the whole enterprise working.

In January 2016, Freud Communications acquired Brew in a transaction reported at $15 million. Brew then had about 20 staff and operated in New York, Los Angeles and San Francisco. Cook oversaw the acquisition. The firm that helped other businesses communicate consequential changes now had one of its own to explain.

An acquisition places unusual demands on an agency leader. Clients want continuity; employees want to know what changes; a buyer has reasons for making the deal. Those are the ordinary questions any acquisition raises. In Cook's case, the episode also became a concrete management credential alongside her client work. She had experience being responsible for the business behind the advice.

Barbie, and the people behind the brand

Mattel announced Cook's appointment on March 6, 2019. Kreiz was pursuing a business built more extensively around the company's intellectual property. Cook had worked with him before, when Brew represented Maker Studios. Their professional connection preceded the new title, a detail that makes the move less of a leap between unrelated worlds.

Her responsibilities were broad. They encompassed the corporate story and the communications reaching employees, alongside the public-facing work. Later descriptions of her Mattel tenure included financial communications, brand PR and corporate social impact. That is a considerable distance from the popular image of a publicist pursuing one more mention.

The childhood connection gave her a human way into the assignment. When Cook spoke about the same brands shaping her son's childhood, she described a relationship across generations. Corporate strategy often arrives wearing a tie and carrying an acronym. A parent remembering a toy gets to the point rather faster.

There is a temptation, looking back at Mattel's film ambitions, to make every earlier appointment a prelude to the next famous release. Cook's actual assignment is interesting enough on its own. She joined in 2019 to communicate a company in transition. The job demanded a clear account of where Mattel was going while its familiar brands continued to mean very specific things to people.

The return address changes

In 2020, Cook moved toward another side of company building, joining Reinvent Capital. The investment firm was associated with Mark Pincus, whose Zynga had been a Brew client. Again, a professional relationship crossed into a new setting. Her role there combined a partnership position with chief communications officer responsibilities.

Investment brings a different audience to the conversation. A company must explain the opportunity ahead of it, the assumptions behind that opportunity and why its team should be trusted to pursue it. Cook's move put her experience with founders and executives inside an investment organization. It extended a career already moving between counsel from outside a company and responsibility within one.

By late 2021, she was working at Age of Learning, the education company behind ABCmouse. A photograph from an office visit places Cook between founder Doug Dohring and communications colleague Jennifer Reza. The backdrop includes cartoon mice and a map of the world. A communications career occasionally supplies its own visual punch line.

A board seat beyond the client list

Cook's work in Los Angeles also reached beyond commercial communications. In summer 2017, the Alliance for Children's Rights welcomed her to its board. At the time, she was serving on the Los Angeles Mayor's Council of Technology and Innovation and the Los Angeles Executive Committee of Human Rights Watch.

The Alliance connection continued through changes in her day job. Its reports listed her with Brew, then Mattel, then Reinvent Capital. By its 2021-22 impact report, she was board co-chair, listed with Age of Learning. The employer changed in the directory; the organization she was serving remained.

That continuity gives the biography a dimension a client list cannot. Board service involves responsibility for an institution and its purpose. The Alliance's work centers on the rights of children and young people, including those in foster care. Cook publicly expressed pride in helping its advocates build a better future for children. Here, too, her role involved standing behind an organization whose work belonged in the foreground.

Signal, with the volume turned down

Signal's California business entity was formed in February 2023. Its website is spare, presenting integrated communications and an emphasis on stakeholders. Cook's current role brings her back to agency leadership after experience inside a consumer brand, an investment firm and an education business.

The firm's work appears in public announcements. In September 2025, Cook was the media contact for Nova Sky Stories' announcement of a new board member, following a $50 million Series B round. In September 2026, Turing's announcement of a new chief information security officer directed media inquiries to Signal. These are different businesses, but both involve leaders explaining a next stage.

A press contact is a modest-looking line. It does not tell you who wrote every sentence or who made every decision. It does establish a professional presence at the moment a company has something consequential to say. For a profile of Cook, those return addresses are more useful than assigning her personal credit for a client's success.

Her interests supply a final, welcome change of register. Cook has said she plays tennis to put work aside and enjoys The Daily as an example of storytelling. Asked what she would do outside communications, her answer was brisk: “A litigator. I love a good debate.” One suspects a loosely supported argument would have a difficult afternoon.

From Brew to Mattel to Signal, the recurring question in her career concerns what a company needs people to understand. Sometimes the answer starts with a financing round. Sometimes it starts with a toy a parent remembers. Either way, the explanation has a job to do.