Hairline Comparison

Alright, listen up, you big dummy! This joke is making fun of someone's hairline. You know how when you peel a Reese's cup wrapper off, especially from the bottom, it often leaves a messy, jagged, or uneven edge of chocolate or peanut butter? Well, the joke is saying this person's hairline is all messed up and uneven, just like that! Based on this, you probably need a mirror, and maybe a better barber.