What are the specs of this tank?
Wattage, gallon, Co2? Pressurized or DIY, gravel, etc?
Looks good for now, until you get plants.
I would go for some fast growing stems in the back and plant the glosso all over mixed with the hairgrass. Hopes this helps, somewhat.
Nice start off, if you are interested in hairgrass PM me, I have too much from when I bought and I divided my hairgrass evenly in my tank and had extras so if you need some, let me know. Other plants I would go with is java fern, attached to driftwood. Dwarf sagitaria for background, and water wisteria in the background.
I think some Blyxa japonica or E. tenellus would look good around the rocks, with either glosso, mini-glosso or HC in the foreground. A few well placed sprigs of hairgrass would also look good around the rocks.
I also think I would try and move the rear rock a bit more off-center and swap positions of the front rocks and move all of the rocks closer together. I would use some taller stem plants in the corners to try and hide the equipment as much as possible.
Tanks specs as mentioned by Erirku would be a great help. It's hard to suggest plants when these parameters are not known.
To take a page from Amano's work, consider the dwarf hairgrass in the back with a little Echinodorus tennelus here and there to break up the monotony. Glosso would look great in the front and be a nice contrast in leafe shape and color to the background. You might try to find some larger/taller rocks adn you rtank is very tall so you have lots of vertical height to play with. I agree that you might want to consider some stem plants or taller grass plants in the back left corner, or even both back corners. Isoetes, Crypt balansae, non-dwarf hairgrass(Eleocharis vivipara) or even Valisneria species would work well for for that, if you decide to go that route,
Whatever you choose, I would definately recommend that you do start with some fast growing stems of Myriophyllum, hornwort, rotala species, watersprite, etc. in order to help with nutrient issues and algae problems. As the tank matures you can remove these palnts leaving only what you want.