I adore her dress and the room...but that doesn't look very comfortable. :-/
Sometimes realism is sacrificed for composition. But that does look like it would give her a neck ache.
Maybe it's supposed to be a sort of snapshot of her right as she's shifting into another position? Look at the way she has one arm holding herself up, and the other arm smashed into the chair. It would be odd...but I'm just going to imagine that's what it is so it makes more sense to me. :-P