The key to interviewing is to eliminate distractions that may keep the interviewer from hearing what you have to say! I’ve had recruiters tell me that while they are not against tattoos and/or piercings, but they can be a distraction. With very little time to make an impression and sell yourself, it would be unfortunate if the interviewer never heard what you were saying because they were distracted. Creative and technology industries are usually more open and less distracted by body art so the guidelines are different. But if you are not sure, then I’d suggest going toward the conservative side and covering them up…especially on your first meeting.