What are "Girls" star Lena Dunham and "Mad Men" actor Jon Hamm doing together?

The young and hip Dunham introduces the new The New Yorker iPhone app to Hamm and the world in a five-minute short she created, which is set on Hamm's faux talk show.

As a late night host in the video (above), Hamm says, "I don't know what an iPhone is, I've never heard of The New Yorker, don't know what an app is."

Luckily, Dunham has come to the rescue with a clip from her new film. The camera pans to a fim-within-the-film of Dunham portraying the editor of The New Yorker and yelling at her "Girls" co-star Alex Karpovsky about the importance of an app.

Dunham has a relationship with The New Yorker that extends beyond introducing its updated technology as an essayist for the magazine. Not only did her ode to Nora Ephron appear in the magazine, but a vaguely fictional essay about her first love was released yesterday.

"Girls" returns to HBO in January 2013.

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