You are actually boxing it in - with the tall unit to the right of it and then a shelf across - it would look odd - even assymetrically. Perhaps consider three floating shelves to the left of the TV.

A novel idea I have come across is to paint the area behind the TV black so the TV doesn't stand out so much.

I was thinking of something more like this - rather than an entire wall. Also frames in contrast such as black and white and white frames can look stunning. But leave it to OP

I never hang anything on a shelf above TV unless it is part of a cabinet. I would be concern about knocking something over while cleaning shelf. I also don't like to hang anything really heavy above bed . I like light canvas artwork.

I love the idea of a floating shelf but not really crazy about it

I would say no floating shelf. I have the similar set up and at one time thought to put something on the wall above the flat screen tv, but I said I rather look at the tv and not get distracted by whatever is above the tv. Plus, it is too much going on around that space, especially when you the tv is on.

Just leave it as is or paint that section of the wall charcoal & watch the TV disappear.