Depends how it's done Puddi. If it's done as part of a cosmetic surgery or indeed by some random beautician then I agree, some scary results can occur! I've actually got the top line on my eye done as well (I'm the nurses pin cushion!)
However the reason the nurse was learning how to do it was because this was just a part of the course she was doing that she needed to pass. She does medical tattooing (private as opposed to NHS alas) which means if you've had breast reconstruction, burns, penis reconstruction etc... she can tattoo nipples, veins, skin, pretty much anything that make people feel normal really... So I was in pretty safe hands. The eyebrow, eye, lip and cheek thing (not done any of the latter) is also useful for transgender patients, particularly males as it creates a softer look.
Bet ya didn't know that eh?! ;0)