Oh man, perhaps more reading and observation is needed?
Oh yes.

There's always more to learn.
My bees 'play' well with others and present more than just two types of behaviors/dances/shuffles, inside or outside (same can be said for some humans). It's never a dishonor to plead ignorance, especially when it comes to beekeeping. I misread OP description that bees "were at the top just under the roof"
What is your 'real' question FRAMEshift? What are you trying to say? Just spit it out man. Specifics?
I don't know the specifics. I was just intrigued when I thought you were saying there were other behaviors on the outside surface of the hive besides washboarding and bearding, which are the only two I know. I was hoping you would mention some other "shuffle" or "dancing" movements you have seen. I know lots of other behaviors inside the hive or at a distance from the hive but only two on the outside surface. So yes, I happily plead ignorance and anything you care to share would be appreciated.
So........Why do bees washboard?
I read some research last year (I don't have a reference) saying that the bees are marking the entrance with scent. I think the point was that instead of just fanning it into the air, they are scratching it into the wood surface to make the entrance identification more permanent.