Hmmmm....Of course, the obvious "You can't judge a book by its cover" would be the natural cliche twin. But let's think a bit broadly here:
1. The eyes don't always reveal the soul
2. An eagle looks differently, depending if you are a photographer or a mouse---you could stick in any animal with a predator/prey connection
3. Sometimes, those Jelly Bellies can be decieving!
4. Trying on a lots of glasses makes one see more clearly
Hope that helps!
You could say that the Sun may rise in the east, but it surely sets in the west. How about, "Where one sits depends upon where on stands."
Perhaps the following may be of use to you:
-An interpretation of one's character may be very different from another's perspective.
-People are complex and are not 'flat' characters.
-People react differently in different situations; you cannot 'pigeon-hole' people.
-Character archetypes do not hold true in complex storylines like 'Silence of the Lambs'