In my personal experience with addicts, tweakers (someone who is addicted to drugs, usually a form of methamphetamines, like suboxone, etc., or "uppers" like Adderal) almost always have an oral habit or "tell" in card playing terminology, that gives their addiction away visually. That's why they suck on things: suckers, cigarettes, e-cigs (the latest craze is an empty e-cig). Recently, I saw a famous TV personality walking around with a baby pacifier in her mouth. Dead giveaway in my opinion. That's exactly what Justin Bieber is now seen doing: sucking on suckers all of a sudden. Big sign, along with irrational and aggressive behavior (egging the neighbor's house).
This woman in the above photo also has an exaggerated facial expression to go along with her tweaker mouth. If, she is, in fact a tweaker. She could just be exhibiting facial expressions common in OCD mental illnesses, or both. Lately, I've been noticing the faces people make while looking at their cell phone texts, etc. I'd love to compile a video of the best ones I've seen, complete with captions of what I think they're looking at. If women only knew the ugly faces they made, they'd be horrified. Reminds me of an old Golden Girls episode in which Blance Devereaux was shown (with a hand mirror) what her face looked like from below when she was "on top". She exclaimed that she'd NEVER have sex in that position again. I can remember looking at myself that way in a mirror and being equally as horrified. Then you look at yourself the opposite way (with the mirror above your head, looking up into it) and you look younger. Hilarious. Instant face lift.
Oh, and another hallmark of a tweaker: The inability to tell the truth, or to exaggerate reality.