This is a very realistic picture. In fact, that's probably my biggest compliant. It comes off as too creepy. Still, it's not THAT creepy. I think you have most of the facial features emphasized properly. Despite the title, it's not really about the lips.
Everything comes off so three dimensionally in this. It almost looks like a clay statue. This guy looks pretty sad. You certainly have a well developed and unique style. That's always good.