Continuity mistake: Frasier is holding a bottle of bubbly during the scene when he, Niles, Daphne, Annie and Guy are in Niles's bedroom. As he walks to the door, he is holding it towards the bottom but when the shot changes he is suddenly holding it around the neck.
Continuity mistake: Early in the show, Frasier, Niles, Daphne and Martin are talking about going to The Ski Lodge. Daphne is holding a laundry basket - the laundry items under her elbow change during the scene.
Answer: Nanny G (Nanette Guzman - played by Laurie Metcaf) has been a children's entertainer for twenty years, and tells Frasier, "Do you know what it's like to play the same character for 20 years?!" The joke is that Kelsey Grammer has been playing Frasier Crane since 1984, when the character first appeared on "Cheers", so Kelsey in real life has been doing just that!
Super Grover ★