It seems that the closer you get to condensing narrative form, the closer you get to the essence of a joke. (I wonder if this would work in reverse--if something about a skeleton asking for a beer and a mop were extended, whether it would become a serious reflection on fate/destiny).

In any case, I enjoy this kind of wordplay which is not only clever but helps deliver a dry humorous tone. I commend your punchline. Also probably a wise move to structure it action--> background --> gag, rather than saving the piemine for later; makes it easier on the reader.