A fellow artist recently asked me if there was and danger in showing all of your art licensing collections. This, like everything, is very personal for each artist. If you show every scrap of your art work, it unveils some of the mystery of your work, and it also opens you up to copy cats. If you hide and password protect your work, no one sees it and it can be a hassle for art buyers to remember your password and have to sign in every time they want to browse your designs.
For me personally I share everything because I'm trying to make a name for myself and get my art out into the world. My feeling is that if someone copies my work they have no originality of their own and will eventually run out of steam anyway. When I'm more well known I will probably not show everything. Cindy Ann Ganaden deals with this issue by password protecting her collections and just showing some teasers on her site: check it out! I think this is a good compromise because it gives people a good feeling of what her work looks like without bearing it all.