- It's clear and understandable at a glance - there's a girl's head on a spoon.
- The proportions are right - the head is not too big and not too small, so it's possible.
- It's funny - there's a girl's head on a spoon (so I don't care how it's done.)
- But I think the most important element is the shadow underneath. Here she is without the shadow (in an admittedly bad clone-tool erasing job):