Where to draw the line between derivative_work and third-party_edit?

A derivative work is clearly dependent on another work or image, but within that categorization there is a great deal of latitude, with things like vector trace and colorized on one end, and on the other posts like post #4336806. Despite being derivative, a derivative work can still be considered a distinct "work". Conversely, a third-party_edit is considered a mere modification of a work.

While doing artist research on post #4644800, I noticed that the post at yandere #817908 had been flagged for deletion for "Mirror image copy". Danbooru's Find similar function didn't return any hits, but looking into it further turned up post #3931971. With that in mind, should #4644800 be tagged as a derivative work or as a third-party edit? Should an artist tag for the pixiv account that posted pixiv #91307377 be created and applied to #4644800, or should the artist be sakura honoka (srhk0623) alone?

Arcana55 said:

While doing artist research on post #4644800, I noticed that the post at yandere #817908 had been flagged for deletion for "Mirror image copy". Danbooru's Find similar function didn't return any hits, but looking into it further turned up post #3931971. With that in mind, should #4644800 be tagged as a derivative work or as a third-party edit?

Derivative work, IMO. If you mirror the image and compare it to the original, you’ll notice that the whole image has been redrawn, so it’s not simply an edit of the original.

Should an artist tag for the pixiv account that posted pixiv #91307377 be created and applied to #4644800, or should the artist be sakura honoka (srhk0623) alone?

I think the artist tag for the post #4644800 should only be the pixiv account that posted pixiv #91307377.
My guess would be that most artists wouldn’t want to see their name on possibly mediocre copies of their original art. With the derivative work tag and the parenting, it should be obvious enough who made the original art.