Those are the same criteria that I use when I submit some awesome art that I see in the potentials room in promo-mentors so hehe.
How about for the subject itself does it need to be an original subject or are you okay if it something inspired by a movie or image of a movie say a portrait of a Marvel character.
To be honest, like I mention in the last example, I can appreciate a drawing using a guided image or based on on a movie or anime, but I find it more amazing when the artist creates something out of thin air.