Re: Questionable Explanation
It's a really grotty video. And doesn't make much sense.
It looks like the robot removes the White Queen on D1. (Why?) The kid then moves the castle from its starting position to that square. It's look like he's still holding onto the piece (castling?) when the robot goes for his finger
Speculation: the AI thinks the arm failed to pick up white queen and is re-attempting the move.