What's going on with that stair-like line on their hair near the ground and the kotatsu's trim?

FJH said:

What's going on with that stair-like line on their hair near the ground and the kotatsu's trim?

There's a bunch around Mokou's feet and under Kaguya as well.

FJH said:

What's going on with that stair-like line on their hair near the ground and the kotatsu's trim?

What line? I see the divisions between the tatami mats.

_cf said:

What line? I see the divisions between the tatami mats.

Maybe it's a browser thing. This is what I see in Firefox.

OOZ662 said:

Maybe it's a browser thing. This is what I see in Firefox.

Same thing in Chrome. It's not just stair-like, but near Mokou's right knee, it looks like what a machine vision algorithm would produce.

Opera user, I see 'em too in the full-sized image.

You're right: with the image on 100% I see them too. Actually, looking at 100% there's lots of coloring mistakes everywhere that's not around their faces, so my guess is that the artist concentrated their attention there, and painted the rest of the picture carelessly. Those stairs look like artifacts generated by some combination of selecting > painting > moving layers.