Your artist may like a picture of your tattoo for their portfolio. They'll clean it up real good, and sometimes even apply a hot towel to it first. Then they'll take a picture, and this is a good time for you to get a shot, too, if you brought a camera along. Taking a photo after the protective ointment is applied causes a glare, so it is best to do it now. If for any reason you do not want the artist to take a photo, just say so. You are not under obligation to let them.
http://tattoo.about.com/od/tattoo101/ss/tattoo_process_8.htm
