hyperion, I think in general you have a natural flair for good presentation and I admire your desire to refine the skill with feedback and critique. I'd like to see more definition of a dish's ingredients/components, as though its photo alone could stand in place of the dish's written menu title.
Use a light reflector. You'd be surprised how effectively a sheet of white construction paper can fill in and diffuse the harsh shadows. Or, cover a sheet of cardboard with aluminum foil. Some means (a clump of playdough, etc) to hold the reflector in place, and free your hand, will help.