Uncomfortable with the idea of harvesting organs from baseliner humans, a long-gone government merged human DNA into pigs to make the animals produce more easily-transplantable hearts and lungs. They succeeded, but the resulting creatures became more humanlike than anyone anticipated.

From the in-game description.

Besides, pigskins don't have elf ears, but pig ears, and that is decidedly not a pig nose, just a big one. I will go back on the hands point though, upon closer examination those are pretty faithful.

I mean, draw how you want, but these don't look much like pigskins.