I would attribute his actions to "structural tension". Structural tension is the reason we still watch a movie even when we know what's going to happen next.
Our mind is a constant prediction-machine. We're continually predicting what's going to happen next. This happens even when we're sleeping. When there is a constant sound in the background while we're sleeping, sudden silence is what is going to wake us up.
I saw the reaction video of a guy playing a first-person-shooter game once, as part of a game design discussion. He came into a virtual room and shot everything dead. Then he saw a large virtual aquarium. He shot one bullet hole at the aquarium around its mid-level. Then water starting pouring out of the aquarium at that bullet hole. The guy playing waited, waited, waited, patiently looking at the aquarium. Then when the water stopped flowing when the water finally reached the level of the bullet hole, the guy playing had the biggest smile on his face. His prediction had become true!
And while virtual reality doesn't always mimic our actual reality, and our predictions don't always come true in a virtual world, so that could explain the player's curiosity and positive reaction. But I think a similar thing could be said for young kids. It's a new world to them. Their verbal skills are getting better every day. And perhaps, when making a verbal request they can see their parent's actions as an extension of their own, and derive personal pleasure when the action is finally completed, the prediction was correct, and the structural tension is gone.