This is not a duplicate, as far as I can tell. It's not the exact same image (although I can't spot the difference by eye, the file is a slightly different size). And this one is still up while the older one is deleted, and there must be some reason for that. (I made a mistake and forgot to set the older as a child when I first uploaded, and I also accidentally copied over the bad pixiv id tag.)
This is not a duplicate, as far as I can tell. It's not the exact same image (although I can't spot the difference by eye, the file is a slightly different size). And this one is still up while the older one is deleted, and there must be some reason for that. (I made a mistake and forgot to set the older as a child when I first uploaded, and I also accidentally copied over the bad pixiv id tag.)
It was tagged duplicate by nonamethanks's bot, because it's a pixel perfect duplicate. The 10kb of difference in size is a discrepancy between image hosting sites(or changes over time in how one site handles compression/meta data), there's no actual visible difference in the two images.