post #5125409 was removed for Inferior version/duplicate of post #5123496 But the one I posted was from weasyl which the image file size was clearly bigger than at other sources. This goes for all other related deleted posts of mine.
My question is: How exactly are they inferior or duplicates?

They're visually the same so the one that was posted first was kept

Higher filesize is not necessarily higher quality.

lafcadio said:
Higher filesize is not necessarily higher quality.

Indeed, I've seen 80KB 73-color PNGs better than 1MB+ files with 'more colors thus better!' when in fact, the colors only came from resampling the image at a higher resolution. You'd zoom in on the 'inferior' one and realize this quite quickly. Even funnier when it's a different PNG that is resaved in an editor from the JPEG resample. How a sub-100KB file gets inflated to 1MB+ and loses detail every step of the way.

In this case, they have the exact same pixel values, and when creating a pair of BMP files from them, the only difference was 2 bytes (one is marked 72x72 DPI and other isn't).

PNG has an interesting situation where a file can be more aggressively compressed, and get somewhat different sizes. There is no canon encoding of a given set of pixel values, other than option settings for a given version of a given encoder. This is why Danbooru variants often have a pixel hash in addition to file hashes.