I Only Have Eyes For You - S2-E19
Revealing mistake: After Buffy has entered the wasp-filled school there's a shot of the others standing outside waiting for her. In the establishing long shot if you look closely you can see they used the same shot as earlier in the episode - Buffy is standing there with them. (00:34:10)
I Only Have Eyes For You - S2-E19
Visible crew/equipment: After the history teacher writes, "Don't walk away from me, bitch!" on the chalk board, Buffy says to Xander, "I'm telling you, something weird is going on." As she says "something", a boom mic is reflected in the window behind her on the right.
I Only Have Eyes For You - S2-E19
Continuity mistake: When Buffy is waiting in Principal Snyder's office, the 1955 year book slides off the bookshelf and lands open, but when Buffy walks over to pick it up, the book is closed.
I Only Have Eyes For You - S2-E19
Audio problem: When Giles looks through the window of a door at the high school and sees the janitor yelling at the teacher, the janitor's lips don't match with what he is yelling.
I Only Have Eyes For You - S2-E19
Continuity mistake: When George shoots Mrs. Frank, her body falls off the balcony headfirst on a closeup shot. She flips in the air once on her way down. But in the following wide shot, she flips in the air on her way down again.
Continuity mistake: When Willow is interrogating Jonathan, she makes a comment about how he resented being pushed around. In the first shot, she's facing him. It then cuts to the opposite angle, and she's facing sideways. Then, in the very next shot, she suddenly turns 180 degrees between cuts after walking by him.
Other mistake: After Gage turns into a monster and fights Buffy, the two monsters slide into an open grate. During the shot, there's some sort of weird "glitch" in the background where the garbage can and wall seem to slightly move. All I can assume is that a few frames were trimmed to speed up the shot and it may have exaggerated subtle camera movement, making the background appear to "jump" slightly.
Continuity mistake: When Buffy, Willow, and Cordy are talking at the swim meet (after Gage waves at Buffy), the way Buffy is holding her hands changes back and forth between two positions as it cuts between her and Cordy. Seems two different takes were used, and she had her hands in slightly different positions in them.
Continuity mistake: When Angelus is spitting out Gage's blood, he goes from straight up to leaned over between cuts.
Continuity mistake: After Willow says that the student was killed by being opened up like an Oreo "except without the chocolaty cookie goodness," Buffy's hands go from together to apart instantly between cuts. She then puts her hands back together only for them to be apart again in the next shot.
Continuity mistake: When Buffy is talking to Cameron in his car near the start, the amount of light on Cameron's face coming through the windshield changes between cuts a few times. Sometimes the top is up over his eyes, sometimes it's down by his nose, etc. Also, depending on the angle, sometimes there's a purple glow on his face and sometimes not.
Continuity mistake: When Buffy and the guy are talking at the beach in the beginning, right before they hear a voice scream "Somebody help me!", the guy starts to turn to look at the tide. However, in the next shot, he's instantly facing Buffy again and then turns to face the tide a second time.
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.