I didn't look wrong.
I studied it like I do every piece....
I've been doing htis for years, my eye isn't off by much.
I'm very good at judging distances and such on paper, like line length and things.
Your sketch is disproportionate.
It's fairly well done, but no where near perfection.
Like I mentioned, I can tell who it's supposed to be...but thats it.
Plus, I hate the way you did the clothing.....it looks too starched....WAY too stiff.
That's my critique of your piece.....
My one piece of advice is:
if you can't take critisism, don't bother posting your stuff.
Just saying.