Close
I've noticed a few times but the dupe/similar search doesn't seem to work when one of the images has a border and the other one doesn't, like these two;
https://yande.re/post/show/182229
https://yande.re/post/show/181155

Even an outside iqdb search gives only one image here.

Well, just something I noticed, I can always scroll through the artist's images if I suspect there's a dupe that should be tagged by parent/child...