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

Just compare the size and shape of the left ear. On the right, it's longer and slimmer than on the left. In fact, it's looks longer and slimmer than any ear should be. And it's because they adjusted the aspect ratio of the whole image to lengthen and narrow his face. His ear got caught him in the sweep.