Lets see:
1.The Rock on the left has ugly textures. Do something about it, replace it or maybe delete it and place something else there.
2.The tree trunk in the bottom right corner cant grow on rock tile.
3.The mushrooms on the rock seem floating.
4.The ruined pillar looks bad next to the tree, place it somewhere else.
5.That book seems weird being there.
6.The background is empty, fill it in.