Lay off Keira, she's lovely. A wise MNer once said "KK is not the most beautiful film star in the world. And she is not the best actress in the world. But she does get all the best roles. Which suggests that people really really want to work with her. It says good things about her personality."
Of course it looks bizarre - it's an intentionally extreme high fashion trompe l'oeil look. Fashion doesn't have to be conventionally pretty and flattering all the time - one of the fun things about being a staggeringly beautiful millionaire film actor is that you get to wear the mad arty stuff sometimes instead of what Trinny and Susannah would recommend - it's what I like about Emma Watson and Tilda Swinton.
I'd totally wear that outfit to a party where I'd be amongst friends who appreciated an effort, though not perhaps in Keira's size.