Since his eyes are on the side of his head he should only be able to see the perimeter of his eye sockets, if any light managed to reach them. Mario is blind :(
What proof do you have that he isn't displacing the supposed "background" like a bacteria moving in a petri dish?
Calvinball rules say the volume of bushes, as a liquid, aren't compressible. Pixels are not moved, outline is overlaid by the body without surrounding the body.
Perhaps they are transmogrified?
Then Mario is above them during the transmorgrificalization.