MindFuck. when you see it you'll shit bricks.
if you do not recognize it immediately what it is, then notice your state of mind. notiice that it is, to some extent, confused
some people, when they first see this picture, say, "i think it might be a dinosaur." but they say it with uncertainty. they're not quite sure. they believe it might be yoshi jumping out of an egg. (that's what i thought when i first saw the picture.) but there's no sense of seeing, no conviction that you know what the picture depicts.