Continuity mistake: Huge continuity gaffe. When Anya and Xander see Spike and the robot in the graveyard it is nightime. Xander goes back to speak to Spike almost immediately and sees Glory's followers kidnapping him. He wakes goes back to Buffy's house and from there they, again almost immediately, go looking for Glory's house - and it is the broadest of broad daylight. You could see it was still night before they left through the windows of the house. It also begs the question of how they got Spike from Glory's house back to his crypt in the sunlight since they had no blanket. (00:26:20 - 00:28:50)
Continuity mistake: As Spike is escaping Glory's apartment, the doors for the elevator that he tries to get into close in front of him twice.
Continuity mistake: When Glory punches Spike into a wall at her apartment, some blood appears on Spike's lip after he hits the wall which wasn't there before when he hit the wall.
Continuity mistake: When the gang are fighting Glory's minions, one of them knocks Giles to the ground and then tries to choke him. As Giles hits the ground he lands facing downwards so we can't see his face. But when the minion is chocking him in the shot immediately afterward, he is suddenly facing upwards.
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.