Hm
I still don't get how you're referencing the original pic. I made a GIF, and it appears you have matched up the shape of the cat perfectly.
http://www.newgrounds.com/dump/item/9d2a68eb6408d0d2ba3bbf5660e6d8a8
How are you starting off these paintings? I'm getting the impression you're simply painting over the original. Which is a bit of a shame, cos otherwise the brushwork in this pic is pretty nice, and pops out.