The game: Hammer vs. Doughnut
The players: Chris gives her both toys (the yellow ring apparently is "doughnut") and he encourages her to bang the two toys together while he sings "Hammer versus doughnut! Hammer versus doughnut! This is what happens when an unstoppable hammer meets an immovable doughnut!!" He laughs. She giggles uncontrollably and battles on with the aforementioned hammer and doughnut.
The conclusion: I realize that she is all him, through and through. I live with two strange birds.