If you take an emo kid grocery shopping.
You get to scan their wrists for discounts!
Alright listen up, buttercup. Emo kids are known for cutting their wrists, right? So the joke here is that if you take one to the grocery store, you can scan their wrists like a barcode to get discounts. It's funny because it's dark and plays on a stereotype.
Adolf Bitchler
Nice one