I think adding more photo canvases on the wall is a wonderful idea! That would be a personal and unique-to-you art installation that would provide a great deal of interest on that wall. You would want to determine the arrangement in advance, deciding how many portrait and how many landscape canvases to add, and then perhaps do a mockup with paper sized appropriately to represent the canvases, to figure out exactly where to hang everything for a cohesive and aeshthetically-pleasing look. Don't worry about the corner - you don't need anything there.

I think you should move the floor lamp to that corner so its illumination is centered on the sectional.

Do you need a walkway behind the sectional? I understand when furniture can be moved away from a wall for a better layout, but in this case, I'm wondering if you can move it closer to the walls so you can move the floor lamp to that corner, where it makes more sense.