Why are mesoamerican and southern American depictions of Humans so "blocky"?

by CrtSld

I've been visiting a museum with a friend and we noticed that, in comparison to Egyptian depictions of Humans American civilizations used to depict humans as really blocky and very symmetrical beings. Is there a particular reason for that?

CrtSld

Addendum: stylised is a good term for that kind of depiction as well, while European and Asian civilizations had a very true to life style for the most part