The callback that handles the initial sizing/scaling for images was

sometimes running before jquery finished setting the initial-width and

initial-height data, which could result in one of the two images in

the two-up view being scaled and one not. This change adds a _.defer

call to unwind the stack before we trigger that callback.

Loaded a diff that had a bunch of changed images with @2x versions. Saw

that I was no longer able to trigger the case where one out of the two

images was full size and one was 50%.