In those rare instances when nudity is shown in a nonsexual context in a Hollywood movie, it is rarely casual. Sometimes it's a very big deal, like Julianne Moore's famous pantless scene in the Robert Altman film Short Cuts [link very NSFW]. She's having a major argument with Matthew Modine's character, and when he registers that she's half-naked, he screams, "You don't have any panties on!" In other instances, nudity is played for laughs—this is often the case with male nudity. In a DoubleX article from last summer, Willa Paskin noticed the trend of flaccid penises showing up in comedies like Forgetting Sarah Marshall. In that film, Jason Segel's character surprises his girlfriend naked when she walks in the door after a long trip. When he realizes that she is dumping him, he demands that she break up with him while he's still unclothed.
Even if a mainstream movie wanted to employ the casual nudity of a mumblecore film, it would be difficult to pull off. Mumblecore movies are highly collaborative affairs, often made by close friends. Typically, the actors also have writing credits and do some work behind the camera. Director Joe Swanberg, for example, is naked on-screen in Nights and Weekends and in his Web series Young American Bodies. Lena Dunham, the writer, director, and star of Tiny Furniture, a recent festival darling, told me over the phone, "I've never gotten naked for another director, which for me is defining." She appears in varying degrees of undress in her first feature, Creative Nonfiction, and in Tiny Furniture. Her co-stars in Tiny Furniture are her real-life mother and sister, so when she is walking around with no pants on it's that much more of a safe space. This intimacy would be tough to manufacture in a big-budget movie, not just because it's rare for A-list actors to know one another so well, but also because there are so many more crew members involved in a bigger productions.
Perhaps the most significant reason true mumblecore-style nudity is unlikely to ever really make it into the mainstream comes down to money. Mumblecore movies are so small that they do not get rated by the Motion Picture Association of America. If they were rated, most of them would likely get the dreaded NC-17. A quick perusal of the top-grossing NC-17 films shows that the rating means comparative box-office death.
The earthy feel to the films that Greta Gerwig and her cohort have developed may "blossom and cross-pollinate with other, older strains in American cinema," as Scott tentatively predicts in his essay. And while true mumblecore-style nudity might never show up in a box-office blowout—as Dunham says, "It's not like you're going to see a James Cameron movie with chubby girls naked"—it could show up in smaller, lower key mainstream productions. If directors are looking for an example of how this might work, though, they should skip the painful sex scenes in Greenberg in favor of one that really does capture the spirit of the Gerwig aesthetic. Toward the end of the movie, on the eve of an emotionally fraught event, Gerwig dances drunkenly around her apartment in tights and a shirt. She's not naked but looks like she's taken off an uncomfortable skirt in order to relax after a trying day. Who among us has not performed this sort of half-clothed ritual alone in our rooms? It's as vulnerable and true as that Corona-sipping sex scene is brutish and contrived.