The human body, particularly the face, is among the most recognisable objects ... part of the art of personal camouflage is an attempt to partially invert the features of the face, in order to make it less recognisable. Finding 'faces' in natural phenomena is quite common ... the Cydonia feature is merely famous. This doesn't mean that the perceived 'face' means anything ... other than if something looks even remotely like a face, people will notice it. We're designed that way.