Scarlett Johansson is waging a war against typecasting with some upcoming roles, I'm sure of it: First, in Her, she voices a artificially intelligent computer that a lonely dude played by Joaquin Phoenix falls in love with, and in Under the Skin, she plays a sexy, man-eating alien who is sent to Earth to, well, eat people. Really — she drugs them, then brings them to her alien friends, and they all proceed to mutilate their victims and fatten them up just like the witch in Hansel & Gretel, because aliens ain't 'bout that low-cal lifestyle. It's sort of a different role for Scarlett, basically!
Those who are skeptical she can pull it off though, think again. There isn't much here to illustrate what the plot of the movie is — it's mostly shots of Scarlett Johansson being a man-eating alien — but since the movie is based on the 2000 book by Michel Faber, the plot is already readily available online. And right up there, because I just explained the whole movie to you in like one sentence.
The trailer's kind of NSFW-y because it features some naked people writhing, but it actually looks like this is going to be an interesting movie, so call it art or something.