I would define the poetic effect as the capacity that a text displays for continuing to generate different readings, without ever being completely consumed.
As an actor, there's a bit of you that's decided you want to be looked at and watched, but there's a paradoxical bit that wants to run away.
It's kind of part of human nature to want to know the truth or want to be in on the secret. For stories that focus in on that - like whodunits - it's easy to get drawn into.