A cut perhaps. I split my lip once and got that result.

And the thing above its eye could be an extra strand of hair.

Yea i guessed the strand of hair thing, but a cut lip is pretty random.

>>2786
...And Uboa isn't random?

>>2790
True.

I would have thought that the thing on Uboa's mouth and eye are cuts, or scars. But that's just me.

It's a cigarette he's pointing upwards with his mouth. The line above his eye is where the smoke stream from it ecomes visible.