[D]What makes "Meta-SGD: Learning to Learn Quickly for Few-Shot Learning" to work so good? • r/MachineLearning

I'm interested in Few-Shot-Learning, so this paper is really intriguing for me either. I think that I still don't get paper (I'm not familiar with Meta-Learning), but learning algorithm look completely different than in normal supervised learning. So for weight update they use test set (which could be also a part of train set, not sure of proper name, but it would be better if we call it train-test and second one train-train). Do you see the difference? Why they use such idea?