I think it would be a great idea when voting to allow users to turn on/off categories. They could vote only in one category, or could select multiple categories, to give them images they are more interested in seeing. Now that you're including Traditional Art and other forms of artwork, people who sign up to vote should at the very least be able to pick if they are voting in photography, Illustration & Design, or Traditional Art. I think this best benefits the voters and the submitters. If I'm uploading traditional art, I'd rather have people more adept/interested in traditional art, judging my work against others in that category. As a photographer and traditional artist, I'm glad you've included the additional categories, although I wish the traditional art, painting and drawing categories had more subcategories. You might consider adding woodburning, printmaking, ceramics and sculpture as additional categories under traditional art.