Midnight Walker by Chow Hon Lam
Is this clown on the tightrope walking upside down or right-side-up? Without the placement of the moon, you might just assume that the black space in between the buildings is the ground. But since the moon is there, it almost feels as though you are on the ground looking up toward the tops of the buildings (therefore making the black space the sky).
(via Chow Hon Lam)