I believe it is purposely ambiguous...clearly it was made as a circle, but wear, as well as the angle/shadows, make it appear to be a qustion mark (and if I were scribbling something on a wall, I'd certainly scribble it as "that one that kinda looked like a question mark").
__________________
'He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me.'
-TJ
|