The "Face" doesn't really exist, as such, anymore. Or was it simply defaced/obliterated when the Martians figured out we had seen it?

Correct, the “face” either doesn’t exist or has been obliterated via manipulation of the images. But from any lighting condition or angle the very high symmetry of the plateau still persists. There’s a straight horizontal line that intercepts the points where the curve at the top intersects the sides.
Carlotto (and others) have made the point that the plateau is non-fractal like naturally occurring formations. The image has been run thru the software intelligence agencies and the military uses to detect camouflaged military installations and indicated that it’s 97% likely to be artificial.
The weight of the evidence suggests that it is artificial so we should take a much closer look (if we haven’t already).
Different lighting, better definition.