I think if it is in a magazine, I don't mind seeing it modeled. However, if it is a piece that I am looking to purchase, I don't want it "used" so to speak. I do understand about the concern for a model type to be off putting, however, if you are just showing the wrist for the bracelet for example, it would have to be really bad to off put me. Same idea with a necklace, just show the neckline. I really don't have to see the whole head. I don't like to see the mannequin parts, especially the hands with the pinky sticking up...weird! Hate those!
Anyway, I like seeing it modeled on a person as it does give me a better perspective. Although I have seen some cute simple props on Artfire.com . Some use the white bust displays and those are okay, but some use plates, vases, bowls, etc to drape the jewelry and that is a cute idea. Although you probably won't see the whole piece.