@Topsy_Krett this is a duplicate uploaded after the first version, don't set it as parent.
And yet there's still a noticeable difference in file size all the same. You know just as well that there are plenty of other posts on this site that get listed as parents despite many of them having file size differences that are far smaller than these two...
Even if this is a duplicate (with mostly behind-the-scene differences), I think this should stay. But if no one approving it, I'm okay with that. And this is the reason why I always checking the filesize when uploading the existing image from a different source (usually Pixiv).
The filesize means nothing, if you open the pictures and zoom into them you'll notice they are identical. Which means the one that has been uploaded first is the parent and all the other are duplicates.