The problem is that the trees create a kind of frame in the picture, as so:
There’s still a lot of space outside those borders made by trees. That’s not a good composition because you can’t really draw anything interesting there. The eye will naturaly see what’s inside the borders and will miss anything that is outside.
To fix that, I moved the whole image left so that there’s not so much of that useless space on the left. And then moved the other tree more to the right:
Now I am adding more cats and details but that’s not ready to show yet.