the Karen Haircut is the signature piece of becoming a bonified Karen, in addition to the sunglasses, sourpuss lips and banshee tone of voice.
By telling someone they could pull of such a hairdo, your basically saying their personality that of a sweaty wrknkled ballsack on a wednesday morning, with a pumpkin spice latte in hand.
e.g I don't hate Stephanie, but I think she can pull off a karen haircut.