Photo #1 is pretty good, especially if it’s actually antique. As far as the people, the barn and the vegetables, perspective is not off much, shadow and highlight do not disagree much, I’d give it an A.
Photo #2 is hilarious. Everything that can be wrong in a manipulated image is present here. If it weren’t so funny, I’d give it an F.
Photo #3 actually is two men carrying a giant shoe, in my opinion. Where viewers no doubt go wrong is in the assumptions made as a result of the image. I know cobblers and shoe repair shops used giant shoes to advertise their services in the past, so I’d assume that’s what we’re looking at in the photo. Awfully light, though. Papier maché maybe.
Photo #4 isn’t as funny as the giant locust in a duel with a man, and it’s not been cobbled together quite so badly. The main problem is that the “wake” of the fish is unrealistic, and not on the same plane as the rest of the water. So, I’d give it a D-.