There seem to be two dresses at work here: One, a strapless floral evening gown, and two, the pink gossamer Lanz of Salzburg nightie that’s been slipped over it. I can’t figure out what the first dress ever did to offend its maker thusly, but Sienna IS presenting the Breakthrough Prize for the best life-extending achievement in science, so maybe she’s just on-theme. Maybe, just maybe, this is a deceptively Bo Peep-looking second skin that’s actually impenetrable to elements, metal, and side-eye.

[Photo: Getty]