Don't use that - it will get rejected for lighting and composition. There's a large expanse of dark background and wet lime plunked dead center.
Have a look through other threads on this topic (applying to iStock) but you'll need three images of different types/subjects (for example, one portrait, one outdoor/landscape and one studio shot). Good focus, no noise/artifacts, stay away from extreme post processing, no flowers, kittens, puppies or sunrise/sunsets.