Nothing at the hart of the art forms origin. Now some how a pin-up has become so sanitized that I took a look at a pin-up of a motorcycle and it was just a motorcycle. That's not a pin-up, a pin-up of a bike should have a women draped over it like candy melting. Put your hate brakes on the women who model for this art form are not even nude 80% of the time(for hard numbers see my first post -Steeve). When, and if a pin-up contains nudity is up to the artists. Most of the sexuality in a pin-up is in the face and subtle or exaggerated poses with the body. Here 2 should be safe for work pin-ups one's cheese cake. The images are suggestive but contain no nudity can you tell the difference between the two, I can't.