Hiro's avatar just looks like Hiro, with the difference that no matter what Hiro is wearing in Reality, his avatar always wears a black leather kimono. Most hacker types don't go in for garish avatars, because they know that it takes a lot more sophistication to render a realistic human face than a talking penis. Kind of the way people who really know clothing can appreciate the fine details that separate a cheap gray wool suit from an expensive handtailored gray wool suit.