Joss Whedon liked the character of Vampire Willow when she was first introduced in The Wish (1998) so much that he wrote this specifically for her.
The scene where Vampire Willow walks down Sunnydale's main street, finding it full of happy people, is a shot-for-shot recreation of Cordelia walking through the same area in The Wish (1998). However, Cordelia's experience is the direct opposite of Vampire Willow's. Although she never witnesses it, this one shot encapsulates the difference made by Buffy's appearance in Sunnydale. This is especially relevant in Gingerbread (1999), where Joyce questions whether or not Buffy really does any good by being the Slayer.
Alyson Hannigan loved her vampire make-up so much that she was made up again as "Vampire Willow" to attend a Halloween party that same year.
Joss Whedon commented, "God, some of the funniest stuff we ever did was in that episode, but also the scene where they find out that Willow is alive and everybody, everybody, is so goddamn funny. It's Giles, Xander, Willow and Buffy, the fearsome foursome."