The couch is… bottomless? The back of it continues down, there are no cushions. I’ve never seen this kind of error before, is there a tag for this?

WorthlessCurtain said:

The couch is… bottomless? The back of it continues down, there are no cushions. I’ve never seen this kind of error before, is there a tag for this?

We usually use artistic error, but I'm not sure this would count. It does look like the back of the couch continues downward, but the shading below Yor also makes it look a bit curved, like what you'd expect when looking at the edge of the cushions, so the artist might not have forgotten the bottom. It's hard to tell because Yor completely covers where the boundary would be.