While the idea is good in theory, in practice, this would put the convention and pictures behind even more. Even as an attendee, if you put this in a different location the lines would be insane too and you’d miss more of the convention that you paid to be there for.
hot take : considering the crazy prices we pay for photo op (and entry tickets as well) we should be allowed to 1. see the picture after it was took and 2. ask for the pic to be retaken if we don’t like it for any reason