You’d think after all the trouble to disguise it as a rock they’d have devised a means of obscuring those telltale tracks, perhaps a system of brushes and blowers mounted beneath?
I suspect those rock tracks have more to do with thermal expansion and cooling every day than anything else.
When the rock gets hot during the day it expands. When it cools at night it contracts. This causes it to ‘walk’ a tiny bit each day
I would love to have a time lapse camera set up to record it. It is just my theory.