Dude, children get antsy sometimes. They literally have different brain development than adults do. They do not have the same controls and inhibitions.

Children are literally wired for physical experimentation and echopraxia.

Kids also want to be seen as helping. If this robot put a piece down poorly, the kid might be trying to straighten up after it.

All of which are eminently reasonable for a kid who has no concept of operating around dangerous machinery.