I think I like this; it's basically the Platonic ideal of the I Just Wrapped This Bedsheet Around Me dress, but it works on her. It's very glamorous and very, very PRETTY and I imagine Anna Kendrick tried this one on before the Oscars, too -- and should have gone with it. Bonus points for such a cute little bag.
She looks DELIGHTFULLY snooty here -- just a bad shot, I think, but the one that best showed you the detail and (excellent) fit on her bodice. This expression is EXACTLY why she got her current role on Parks and Rec (on which she is hilar).
The back is kind of a snooze, but any attempt to de-snoozify would, I suspect, have been DISASTROUS. Sometimes the back of your dress can just be the back of your dress.