Then you’re not looking hard enough. Look at the boomerang-y bit just right of centre in the middle of the dark base. Look at the tiny little dark bits in the middle that protrude into the lighter section. If you look at the boundery between the rain and the base there are identical details all around it. It’s the same photo. They may have worked the top and the bottom, but it’s clearly the same photo.
I’m with the photographer. His work is used in a for-profit product without compensation.