The Show Where Woody Shows Up - S6-E13
Revealing mistake: Frasier and Woody look at the Seattle tourism book, and in particular a photo of the city. However, you can see there may be some text on the page, but there certainly isn't a photo.
Revealing mistake: After Donny puts the phone onto speaker you can see him deliberately wiping the mustard from the sandwich across his left cheek to prepare for the gag at the end of the scene. (00:06:45)
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 ★