it's like a distilled version of the bushcraft show I guess. There are still lots of trade stalls and schools showing their skills and courses, but not as many as the BS, there are also lots of demos and some paid for workshops to sign up for. Unless I've missed them (totally possible as I'm always working!), the WG doesn't have any talks and 'on stage' type displays/demos and no 'celebrities' to draw people in, which I expect keeps the cost down too. Maybe bushcraft show-lite for a more relaxed feel and community gathering; which would make it a stepping stone to the Moot as the full on social gathering with little trade activity.
There are basically three bushcraft gatherings: The BCUK Moot, The Wilderness Gathering and The Bushcraft Show. Each one is different and I would say compliment each other. I think if you wanted to go to just one, then any one will be good, though which is best will depend on why you are going. I think anybody going to all three will find something unique about each one and not be disappointed that they did. I go to all three now in a professional capacity and I enjoyed all for different reasons (beyond earning a living!), there are certainly familiar faces at all.