Try the gold color from the curtains, it would brighten things up a lot. Also, because of the strong busy print on the curtains, you need to rearrange the frames over the sofa. One large piece would be best, otherwise, try running the frames across in straight lines, as if they were sitting on a shelf. That will help keep the your eye from jumping all over.

Thanks for the suggestions! I agree that the gallery wall looks weird in the photos...it's better in person, I promise. But will consider reworking.

Given the wheat color in your cushions, the pattern in drapes and the casual wooden chair near couch, I think a simple sisal rug (but with a wool blend, as that makes it soft) is a good choice. In regards to the collage, your photos would look better closer together - see below (not placement, just overall feel). When I was doing my wall, I played around with different designs on the floor before placing on the wall, which really helped.

i agree on the rug, though sisal may not be the most comfortable.

Wall let me give you a couple ideas. first put them in the same size frame.

If the drapes are usually open, you could do a multi-colored one...with the plain sofa it could be fun.

You could do a stripe:

I installed a gallery of paintings and prints with the frames level above and below, alternating sizes to fit. I laid them out on the floor before hanging them, and used both gold and silver frames in this group. The bottom frames are about 4'6" above the floor and about 16" above the sofa. Your black-and-white theme would work similarly.