Pandora is the person that looks pretty and innocent, however this is a deceiving character and is sometimes evil or the killer in the movie.
Sometimes there is dramatic irony when we know that the character is bad or evil but the character in the movie do not. However sometimes it is the other way round where we both do not know who is the killer.
EG. Orphan, we know the little girl is bad but they do not.
Scary movie neither of us knew that doofy was the killer.