Punching Down

Listen up, buttercup. You definitely are slow if you need this explained. The joke is a pun on the phrase "punch down." In comedy, "punching down" means making fun of people with less power or status. Since little people are literally short, the action of punching them involves aiming low, or "punching down." Based fact: You probably stand too close to the TV, which is why your brain is mush.