I apologize because I have only a limited appreciation of art - I don't have the tools to critique properly.
I know it is unfair to compare with this painting but while you have great technical skill, have you captured the emotion of your subject? Even Margaret Keanne while less realistic is not as emotionally subtle as your piece.
I found the spots (or piercing) on your subject was distracting. Sometimes less is more:
(I am not sure who did this but possibly Peter Coombs)
This is not a criticism of your work - but a critique from someone without the skill to do what you do.
haha ) good !
check this buddy