hmm theres quite a few things keeping your model from realism.
1. The nose is too weak, jimmy's is very strong and his nostrils are bigger. It also protrudes at too less of an angle on your model.
2. The eyes are humongous, not to mention the wrong shape.
3. The divit above the lip needs to be stronger, more defined. Looks too soft and un real.
4. The bottom lip needs to protrude more, and it come out from under the top one, there is a slight over lap there. On your model they meet at the same place.
5. Jimmy's cheek bones are much stronger and more defined than yours, they stick out from the face more. Your 3/4 view looks very flat.
6. The head on your model is cut off at the bandana, I've drawn in the correct proportions.
7. The neck is a bit far foreward and too straight, it needs to have a curve in the back and meets the torso at an angle.
8. Jimmy's jawline is also very square, you'll need to definately fix this.
9. the bridge betweent eh nose and the forehead needs to be deeper and maintain a curve, Yours doesn't do this as dramatically as the real face, or most faces in general.
ok ive drawn the jaw a bit too low, but it still maintains the same shape. Also the lips need to protrude out alot more, almost like a mick jagger type structure.
formerly KrazyJimmy
Prayers for rain...