What I'm trying to communicate is that I think this part of the description
In most cartoons, there are times when big and heavy characters could accidently or purposely sit on someone to be Squashed Flat, and they would even be stuck on their butts.
is not related to this part of the description
The camera could have a P.O.V. Cam of the person about to be sat on and their butt obscures the camera. Or someone could just have a closeup of his butt.
except insofar as that sometimes the two happen concurrently.