If someone asks you to rate their looks on a scale of 1-10, don’t do it. They’re fishing for a compliment, and unless you rate them highly they’ll be upset.
This sketch plays on that, with a woman desperate for her friend to give her a good rating. But whatever she does, he won’t go above a 4.
Then, there’s a plot twist, with her rating him with his shirt off. And she takes her shirt off and… wow.
Part of the reason this sketch works so well is how quickly it ends. Rather than keep stripping more layers off, they take their shirts off and that’s it.