Rocks, whether you have a lot of them or not, can take a little work to turn them into a nice photo. First - light. You've shot mid-day so you have really bright light on some areas and really dark shadows on others. That can translate into a loss of a lot of potential texture in the high contrast. Shoot on a cloudy day or morning/evening. Second, work on your composition. Right now it is a pretty basic head-on documentary shot. Spend a lot of time walking around it and playing with camera angle. You can make it appear looming on its own or pit it against some other known element in the photo for some contrast. What makes a good fashion photographer great is often being able to work with the models rather than just shoot. Here, your rock is your model, except she isn't going to get whiney, tired, or thirsty.