One of my all time favorites—if you move far to the side the anamorphic skull resolves itself. During the Renaissance it was meant as a visual puzzle to show that perspective was an illusion and didn’t represent true reality. It was also meant to be interpreted religiously—when the skull resolves itself it points to crucifix in the upper-left hand corner. The paint represents religion’s power over knowledge. To me it shows how easy it is to distort reality.