Retouching photos is art and science. Your photo contains more detail than you can actually see. Your .jpg file was retouched by the in-camera processor. That may not result in a the best possible image. The bigger your image file, the more that can be done after the picture is taken.
I recommend you always shoot with the highest image quality setting your camera allows. Memory cards are cheap compared to not getting that perfect shot. Please scroll down to the Retouching section of the Price List and Contacts pages for more information.