Personally I don't think there's any machine learning needed for this (but who knows what they used). If I were to build a replica, my approach would be to grab

Personally I don't think there's any machine learning needed for this (but who knows what they used). If I were to build a replica, my approach would be to grab a decent amount of suitable photos, manually mark the pointed areas in them, and have some sort of scaling/cropping/offset handle near misses. I upvoted the submission because I think it's a cool trick either way.