And thanx for the Publicity Still,too! The woman in the middle of this photo is most certainly real - This is why her hair had to be disguised and also why she wears a body-suit... Her mid-section would reveal a line exposing construction otherwise... like the mannequins.
I would guess this is the same model/actor that's lying in the bathtub.
Maybe the "great Scott" was mixing real people w/ mannequins for better Effect. For example... To enhance the effect of when Pris hides,pretending to be a mannequin. The possibilities are endless,though. The thought that it could be Mary is super kewl! Seems like more editing problems but only adds more layers to the BR mystique