Except it isn't "square." Its an illusion that the human eye pics up on. Any one with a bit of critical thinking and analytical skill will notice that there are only a few features that almost come into alignment.
With the bottom of the screen being south, the SW "side" is comprised of two ridges that run in similar but different directions (the uppermost ridge is tilted slightly more southward);
the NW and SE "sides" are probably leeward side features of the two ridges - the wind blowing to the left and right of the two ridges removing the top layer of sediment to reveal craters/rocks/etc -all giving the illusion of "sides" to a "square;"
the NE "side" is only a short edge created by the windward side of a slope that meets horizontal ground -only a very short edge is noticed and it isn't perpendicular to any of the other sides.
What you've shown us is evidence of the human potential for delusion, however slight. This isn't something to be ashamed of, really. It is a matter of natural selection in all probability. We've adapted to be good at finding patterns in our surroundings. It was only natural that there might evolve some "significance-junkies" that make spurious connections to patterns that barely exist and come to wild conclusions with speculations to match.
Electric_Ashlar demonstrates to us all a very good example of anthropomorphic tendency in humanity. The very same tendency that has led to the creation of religion and belief in man. In caves of early hominids, animal-shaped formations on the cave walls were painted to bring the animals to life. It's this same thinking that drives individuals like EA to see patterns and faces where they don't truly exist.
I propose that this thread be moved to the Human Sciences sub-forum, so we can discuss the anthropology and psychology of this human trait in more detail.
