This is weird. >>2584151
is an absurd resolution picture with the artist's post on FA as the source link. Of course, the pic is so big that FA automatically shrinks it, so what the artist did was include a link to download the higher-res version on Mediafire. Downloading from the Mediafire link gives a 6864x2400 PNG file.
Now somehow a background pony has uploaded the same pic at a slightly larger resolution but worse file type. >>2585636 , an 8000x2797 JPG. And the source was just a direct link to the same Mediafire file from the previous picture. So going to the source and downloading the pic myself, I get the 6864x2400 PNG, not an 8000x2797 file.
So I can't tell if the BP somehow had a legit higher-res version of the pic, or if they somehow snagged some up-res'd preview from the Mediafire page, or they just up-res'd it themselves in Photoshop and called it a day.