The small orange accent beautifully balances the rest of the image and leads the sight toward it. After seeing it, the eye continues following the curved line to the top of the snail. Notice that the photograph is done in the hi-key. It is the overall whiteness that envelops the snail, giving it a soft look and a dominant portion of attention. It also renders colours of the background weak and adds to the mood.
The shallow depth of field strongly points out the snail. This technique is often used in motion pictures. It helps cinematographers achieve a certain feeling or mood that scenario demands.
Enjoy! :)