Contrastive and triplet loss is pretty cool for generating hashes. I'd imagine the trick they are alluding to is a rewrite the loss function to be more aware of

Contrastive and triplet loss is pretty cool for generating hashes. I'd imagine the trick they are alluding to is a rewrite the loss function to be more aware of locality instead of trying to minimize/maximize distance. Or they are just shingling different ML hash functions, which is kinda lazy.