There are discrepancies between the two images below. When combined, those differences make a rebus for you to solve.
OK, I think I solved it. Based on Sid's excellent finds:
The differences are a fish's FIN, a bell that goes DING, a DOOR and an E.
So, FIN+DING+DOOR+E = FINDING DORY, which the fish clue us in on.
(There's actually a clownfish right in the middle there.)
Here's what is missing in the 2nd image:
What are these?
The 1st one is a bell.
The 2nd one is probably a door.
So the final answer:(As found by Walt)
Finding Dory. (Fin(fish), Ding(Bell), Dor(Door) e (y)