Kaley Cuoco didn't appear in this episode because she broke a leg in a horse-riding accident.
This episode introduces Aarti Mann as Raj's sister, Priya. She would be a recurring character in Season Four.
Priya: Besides, I could never bring a white boy home to my parents, they'd have a cow! Which is a much bigger deal in India.
Rajesh: Hey, guys. Guess who I found at LAX? My baby sister Priya.
Sheldon: Excuse me, I object. You propose a guessing game, yet you don't give me enough time to guess. For the record, I was going to say: "Your sister Priya."
Priya: Oh, Sheldon. You haven't changed a bit, have you?
Sheldon: Why would I change?
Leonard: The hope has been that you'd eventually bend to public opinion.
Leonard: You're going to risk getting sleepy in the middle of your thermodynamic fluctuations seminar? You know what happens when you yawn in public.
Sheldon: Everyone will see my oddly shaped uvula.
Leonard: You don't want that, do you?
Sheldon: No. But it's a shame our society mocks the differently uvulated.
Sheldon: I think a more amusing violation of Raj's trust is when Howard convinced him that foreigners give presents to Americans on Thanksgiving.