Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

That's right, Backes: it's a mask.

You can see that her face is too pale compared to her neck. You can see that her neck looks to be too wide, and that's because she was facing the camera at a different angle. 

John Armstrong is correct; there were two Marguerites, just as there were two Oswalds, Harvey and Lee.