What did we learn from the Showstopper?

Almost every week during a series of The Great British Baking Show ™, it is true that the Showstopper Challenge does not represent anything that a typical baker would ever make at home. Therefore, most often we will not study the baker's dishes (since we'll never want to replicate them) - instead we'll highlight interesting elements of the bakes, in terms of recipes you might want to try.