Very Suspicious File

There's something off about this file, I've saved this 16,7 MB PNG image into PNG(yes, same format) with lossless compression (aka no quality loss) and the size went from 16,7 MB down to 1,84 PNG - that's not normal, based on a MediaInfo tool both PNGs share the same compression, yet one has almost 15 MB extra in it, I wonder if the artist snitch something in it?

I scanned the image with exiftool and, turns out there's a boatload amount of dummy XMP tags.

Here's a "preview":

07206811822A8A3B9F1D2210, xmp.did:F87F117407206811822A8B9070A62EF8, xmp.did:F87F117407206811822A982DC1C12CA0, xmp.did:F87F117407206811822AB0751E147B24, xmp.did:F87F117407206811822AB836EFF4D079, xmp.did:F87F117407206811822AC0FFE4F8DF00, xmp.did:F87F117407206811822AC478A9276ED4, xmp.did:F87F117407206811822ACA401DD9ECB2, xmp.did:F87F117407206811822ACAECCC81F43F, xmp.did:F87F117407206811822AD44FB486903C, xmp.did:F87F117407206811822AD68C047971A8, xmp.did:F87F1174072068118F62B1372C696003, xmp.did:F87F1174072068118F62B1DF92171889, xmp.did:F87F1174072068118F62BFD904CF5602, xmp.did:F87F1174072068118F62C20C34D02B56, xmp.did:F87F1174072068118F62C9CC677A1861, xmp.did:F87F1

And there's like a million of these lines

Edit #2
I used an online tool to scan the image and, seems like all the boatload of data is "Classified" as "DocumentAncestors: "; I don't know what I'm talking about, but I wonder if the author saved in the file each and every command used when he made the image from a blank screen all the way to the final result, uhmm...

(See https://brandfolder.com/workbench/extract-metadata )

Likely edit history from whatever software the author used to draw