To answer the question, I don't mind a chick with a small tattoo or a tramp stamp. Covering large parts of the body are a real turn off for me. But your friends back does look pretty cool. It looks to be well done as well AFAIK.
I have a tattoo question. Do people with tattoos get offended by strangers staring at their work? I don't want to offend anybody, but I love to look at people's tattoos. I saw a guy the other day who'd tattoo freaked me out. He was standing in front of me for a little while. At first, it looked like he had just a weird looking design on the back of his neck. But, after looking at it a few times, I realized that there were eyes staring back at me through the design. I guess he wanted to let people know he had eyes in the back of his head.