The title itself (Guess Who's Coming Out Of Joy) suggested that the storyline would revolve around Joy's pregnancy. Or someone actually WOULD come out of her. But we just got to see an old, already seen stuff. But still it was funny.
And what the hell was that lamp about?
Earl saw Joy's pregnant belly and remembered of a lamp that he wanted to finish. And somehow with no apparent reason he started flash backing back to the time when he married Joy and expected her 2 kids that wasn't his. Basically there were a lot of already seen footage from the beginning of season 1 and some new stuff that didn't make any sense. Just made a few details about Earl's and Joy's former marital life. The best part was when Earl's dad threw the gerbals out the window!