LOL. It's a PSA trying to convince kids to drink milk. There were tons of them, but this is the one I remember most.

Hmmmm... it looks like a good portion of the Milk PSAs scroll around on the bottom of the youtube video when you're done. So if you're interested in learning about 80's kid PSAs, click on a few. The one with the little girl in the pink dress in front of the mirror is another one I remember.