Review for NeurIPS paper: DISK: Learning local features with policy gradient

Neural Information Processing Systems 

Weaknesses: My main concerns about this paper are as follow: (1) The main contribution of the paper is not well discussed. It is not the first work using reinforcement learning to learn local features. But what is the most important difference between the proposed method and the others? Using policy gradient for discrete task learning is a reasonable idea. However, more theoretical supports are necessary.