Imagine this scenario. Two people are having a conversation in which one is trying to explain something to the other. During the course of conversation, the exponent asks the other person a question whose answer will finally connect all the dots for that person.
Is there a term for such a question or this technique of explaining things?
Furthermore, how do I describe the expression of the exponent as he patiently (or without patience) waits for the other person to connect the dots? (Ideally I would like to describe it in as few words as possible.)