Continuity mistake: Buffy's birthdate starts at 1979. In "I Robot, You Jane", when the demon pulls up Buffy's file in the school system, it shows her year of birth as 1980 and her year as sophomore. But when her file comes up on the student's computer screen, it's changed to 1979 and that she is a senior. It wasn't until towards the end of season 1 in "Nightmares" that her birth year is 1981 (on her tombstone before she comes out as a vampire). (00:08:30)
Continuity mistake: In the beginning, after the monk traps Moloch and closes the book, the positions of his hands gripping the sides of the book changes slightly between cuts. (Ex. His left hand is lower, then suddenly slightly higher between edits).
Continuity mistake: When Buffy and Willow arrive at school at the start of the episode, Willow is wearing very dark, completely opaque tights that look to be black or at best very dark navy blue. When Xander finds her in the next scene, which takes shortly after on the same day, she's suddenly wearing much brighter purple tights.
Continuity mistake: In the beginning of the episode, when Willow gets the email from "Malcolm" and says "He's so sweet! What should I write back?", she instantly goes from facing forward at the computer to facing sideways at Buffy between cuts.
Chosen answer: Angel is saying that he is still jealous and Buffy recognizes that this is his way of saying he wishes that they could be together. That is why they both smile.