Continuity mistake: When Anya is confronting Dawn about Xander's disappearance and the demon boy leaves, he walks past Dawn and her attention is on Anya but in the next shot you see him walking away from behind and his sleeve is still in the shot as Dawn turns back to Anya.
Visible crew/equipment: In the scene where Anya is going over her wedding vows with Tara, she steps down from her dressing platform. As she steps down, part of the camera can be seen on the far left of the screen, obstructing the shot.
Visible crew/equipment: In the final scene with Anya and D'Hoffryn the edge of the backdrop (and the set behind it) is visible when D'Hoffryn walks around her. (00:40:10)
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.