Oh, this has so many good bits to it. Not only does it illustrate the improvement in relations between Ozai and Iroh after the war, it also shows their differences in teaching style (well, after Ozai's calmed down a bit) and their similarities, if only because they both love tea, but hate how their brother makes it (which must be interesting if you're keeping to your prior canon and Ozai is working at Iroh's tea shop). Also funny how Iroh is merely one of the worst teabrewers, while Ozai is the absolute worst.