Im guessing you have no space on the back side of the wood?
If you can move the wood forward an inch or two you could plant some stems. Some rotala H'ra or other fine leaf stem plant would look nice wrapped around the edges of the wood and continuing behind it. Also I would move the barteri in from the edge of the tank. It is striking and pulls the eye to the corner of the tank. It would make a great focus point.
Hope that helps
And get a background (maybe black). It will be easy to see the scape and work with it, and help the plants pop