The wing structure was the biggest thing I was noticing. The original looks like the wings were just slapped on there, due to them being flat. The redone version gives them structure like a real bird's wing and makes them more proportional to her body.

The change in style is definitely the easiest thing to notice, but the second drawing has a lot of smaller details that are improved from the first one. Things like the texture of the cloth and the detailing on the birds, fruit, and grass have all improved greatly.