This special "episode" is only 10 minutes long. I don't know whether these scenes were scrapped from the final cut, or if they were filmed after the rest, my bet is for the former, then again the scene with the kid here is way better than the one in the final episode. I don't really understand why that would've gotten cut.

There is 0 reason not to watch this, if you followed the original run. It's a gift for the fans, a nice one at that. It's way more relevant to the story, than the Mr Queen special. In fact that is probably the most fun/relevant special I have ever seen, the only problem with it that it's way too short.