There's not really much of a joke here, just an idea of one of the later Galas, kind of trying to use both ideas. I really just liked the idea of Celestia and Luna dancing with each other.
Again, I'm sorry for the variable quality Work has been putting on more demands lately so I often have to draw with little time to correct or to stop and look it over several hours later as with other drawings. After the challenge is over I'll look to doing stuff that takes more time.