Recently overheard conversation

My niece and my son (who are both 3) were running through my house leaving a trail of destruction behind them, when my niece stopped to look at a picture of my son.

Niece: (pointing to picture) Hey Braden, that's you in that picture.
Son: (clearly not yet understanding personal pronouns) You?
Niece: No, you.
Son: You?
Niece: No! You!
Son: You???
Niece: (quite exasperated) NO!!! YOU!!!!!

If this exchange continued any longer, I did not hear it because I was laughing too loudly as I walked away.