Nudity that is about familiarity rather than titillation.
Kissing that is about vulnerability not voyeuristic pleasure.
At least in this film, all they do is kiss (as opposed to Alexander the Last which has a lot of fucking in it). But they kiss a lot and often for considerable duration and in tight closeup. Kissing is where the film locates intimacy, not fucking.
Note the lack of open-mouth, tongue kisses. Swanberg refuses to “keep it real” in that way. Consider someone like John Cameron Mitchell who thinks that the Real is to be found by showing penetration. Swanberg exposes that tactic as a lack of imagination.
Hannah's promiscuity is not celebrated; it is not a source of strength or revelry. On the contrary, it causes all of the problems in the narrative. She is not out for fun, but looking for love. She floats like a butterfly and stings like a bee.
It is hard to watch Hannah (Greta Gerwig) break up with Mike (Mark Duplass) and not because of something gratuitous or shocking. The pain is in the truth of her (and his, but to a lesser degree) acting. It is embarrassing to watch because it is all-too familiar not because it is inaccurate or melodramatic. The viewer is surprised by recognition, not by novelty.
This is what I mean when I say the movie is for adults. I don't mean that I'm a mature grown-up; I'm as immature and as mature as anyone else. I mean that Swanberg and the actors treat the audience like adults. The actors may be in their late twenties and early thirties, but you have to have had adult experiences in order to appreciate their scenes. By contrast most junior high kids can follow and understand the emotional worlds inhabited by every character played by Jack Nicholson, Meryl Streep, Diane Keaton and Al Pacino in the last thirty years. One must be old enough to have gone through a couple breakups, to have done it and have had it done to you, to appreciate her struggle in that scene.