I honestly very much enjoy this piece. I looked at the rest of your art, and though it's all very simple, it all has it's own reasons and it's own beauty.
My recommendation is add smaller details, perhaps wrinkles on the face, or in some of the the other pieces try to add more detail to the background.
My favorite piece by you is definetly the colored clouds. Quite breath taking. I love the coloring, and find it to be quite relaxing. By far my favorite.
Overall, great work. I can't nit pick at things I don't entirely understand. That's your style, I can't tell you how to draw, paint, or... synthesize? Is that what you do with computer art? I haven't the slightest.