i just watched the episode "I Pray The Lord My Stove To Keep" and at the end, it has the cast dancing to some music and it's bugging me because i don't know what the purpose of that was, but it was funny. And why were they dressed up? except for roseanne and dan? thanks.

This is one of my favorite episodes and I watched it today too.

DJ asks Dan about some of his more religious relatives during the episode, and Roseanne mentions that one of the gets up and dances when "he's filled with the holy spirit" (read: drunk). The tag features this relative, and since Dan & Roseanne don't care to have them around, they aren't participating in the "festivities"