It comes as soon as possible, most often before the credits, to hook us into watching the rest of the program. Her un-informed daughter visits the set and doesn't understand her mother's strange reaction. Errors or mistakes cause most sitcom complications and conflicts that is the genre's comic heart. Sitcoms, like most TV formulas, spend more time showing frantic action than developing complex personalities, motives and events. The more the confusion, the more comic the episode.
Individual shows build layers of confusion from a single complication.
Expression and reaction follow each complication, gesture follows reaction, slapstick follows gesture. The broader the action, the louder the laugh track. At the center of the situation, complication and confusion are the real characters of the sitcom. They are the cause and effect, creator and target of the joke, our key to the formula's meaning. The stars merely do what they have always done and will continue to do.