Ages ago when my cousins and I were playing the original Final Fantasy, my Aunt mistook the pillars as generic metallic garbage cans. Ever since then, I have often been amused at gamers and non gamers alike mistaking game graphics for something else.
Example: Many people on this very forum pointed out to me that they thought Emperor Gestahl's sprite looks like a dog when facing forward.
Just now, my girlfriend dropped this one on me when she was watching me play Chrono Trigger:
(SPOILER)
Anyway, share some of your experiences of amusing mistakes similar to the examples above!