It's probably an American thing. Basically it's a 'song' for kids that goes:

"Hi. My Name is Joe. I work in a button factory. One day, my boss came to me and said are you busy? I said no. So push the button with your right hand."

The kid then acts pushing the button with their right hand and you repeat the verse, but substitute left hand, right foot, tongue, etc. In the end you've got the kid trying to push multiple imaginary buttons at once. (It's funny when their reciting the above phrase with their tongue sticking out, lol.)