Some major sponsors make a point of using models that appear under age. I remember seeing a gallery of one well known model from a well known sponsor in her first photo shoots that I thought didn't look a day over 16. It was taken at home with her in a bunk bed too Who sleeps in a bunkbed after 18?
It's all part of the "teen" thing. Met Art has been around for awhile and is promoted by alot of respected webmasters.