A character talks to their reflection in the mirror. Usually, it's a male character giving himself a pep talk. If the reflection talks back, it's a case of The Man in the Mirror Talks Back. If they're practicing a speech to someone else, it can be a Trick Dialogue -- and may feature Unaccustomed as I Am to Public Speaking. If it's delivered to some other object--a pet, a tombstone, a skull--it's a Surrogate Soliloquy. If the character winds up shattering the mirror in a fit of anger or sorrow, it's Rage Against the Reflection. If they say something along the lines of "You Talkin' to Me?", it's a reference to the famous scene from Taxi Driver.