Dopplegangerland

In a sense, this is Willow's version of The Zeppo. Vamp Willow from the parallel dimension is called into our dimension as Willow and Anya try to retrieve Anya's necklace. Again, Willow's magic goes awry and causes more problems than it solves.

In the previous episode, Willow has been jealous and sad; she doesn't want to be everyone's doormat, good old reliable Willow. That point is made throughout the episode, even as she tries to tutor a recalcitrant jock and be cheerful Willow in the fuzzy, funny clothes.

Just as The Zeppo begins the redefining of Xander, this episode makes the audience (and maybe her friends?) look at Willow differently. This isn't about Willow as potential witch, it's about Willow as not-relentlessly cheerful good girl. Even though Willow herself stays perky, the image of a "skanky," sadistic, hedonistic Willow is planted. Typcially, Willow wants to be nice to her evil twin, not allowing the gang to kill her--so in Willow's mind, there is in fact an evil Willow wandering through a parallel dimension.