The model looks a little "choppy". It looks like she was cut out of another image and placed in the white background. When I do cut & paste stuff in photoshop I try my best to smoothe out the rough parts to make it look natural. My suggestion? After you cut & paste, take about a 5 pix smoothe brush eraser and zoom in around the edges and smoothe out the edges. Don't erase too much, but just enough to make it blend well. Someone might have a better suggestion, but thats my 2 cents..