Since the update separating the pupil lineart from the rest of the lion, I've noticed a thin white line in between the eyes of a lion and the rest of the art.
It is particularly noticeable on some lions more than others, but it does appear to be present in all linearts.

I suspect that this may have been caused by the usage of the lasso tool, which sometimes does this when areas of a layer are selected and cut into a new layer. I think it can be fixed by adding a tiny bit more black on the body lineart layer beneath these white pixels, or on to the eye line layer itself!

Here are some examples: