“My mom is coming,” says Pam the receptionist, before Michael responds with his second-ever TWSS. This joke isn’t successful because it’s witty. It succeeds because it wildly caricatures bosses who tell awful jokes. It’s crucial here that both versions of “The Office” pretended to be a documentary. If the actor Steve Carell had debuted TWSS in a stand-up routine, by contrast, he’d have been run off the stage. But in an exaggeration of real life—a mockumentary—even the jokes can be parodies.