This looks so much like our dry creek bed with our little apple tree in the middle. Maybe adding large rocks around the other side of the tree will make it feel more balanced. Also, I like the itty bitty rocks along the outside of the larger rocks.
Adding a Poodles Waterfall-Safe outdoor Water feature for kids and easy upkeep! use to filter grey water to water landscaping and see the flow is cool too. have a pump to recirculate it over the rocks to filter through the rocks