When Milhouse makes copies of Bart's photo, the sign on the copier says "Copies 5¢," but the coin slot says "10¢" and Milhouse uses what looks like a penny.
The windows on the Simpsons' house change from bay to arch.
In this episode, Lenny's voice is provided by Hank Azaria and Carl's voice is provided by Harry Shearer. For the rest of the series it would be the other way around.
During the party, when Princess Kashmir asks Homer to dance, her mouth never moves.
After Carl talks to Homer about Princess Kashmir, Lenny turns around and says something to Homer but no words are heard.
Bart makes 6 check marks on the card he fills out at the Rusty Barnacle, but there are only 5 boxes on the card.
When showing Barney his house, Homer says that Marge must have left the porch light on; but the Simpsons don't even have a porch.