I absolutely love this picture, and I know the artwork of Bruce Timm's that you are referring to, I've always liked it as well.
But this is wonderful, you captured The Joker's expression, & reaction perfectly... Most people seem to think he adores hugging Harley but it the absolute opposite. He hugs her when he needs he to be a good little lackey, of course poor Harl is oblivious to this. You captured her wonderfully as well.
You did such an awesome job... and in the traditional way to boot. You are very talented and I really love your work.