Production number, I'd say, because the WB ran most of the season 2 episodes out of order, so there were a lot of continuity gaps. For example, Mindbender aired a while after Shadow Dance, and they mentioned the dance hadn't happened yet! Another example is Fred's mohawk. It's shaved off in Shadow Dance, but in Walk On The Wild Side, which aired much later, it's cut off by Boom Boom.
"As I bit into the nectarine, it had a crisp juiciness that was very pleasurable, until I realized that it wasn't a nectarine at all, but a HUMAN HEAD."