I would paint the whole bump-out black so the TV disapears into the wall.

I was thinking something like this.....

Your TV is much too high for ideal viewing and too wide for the mantel. Painting the back wall black would help camouflage the TV screen. I show the fireplace entirely painted in black with a wood mantel (keeping your black tiles) and flanked by narrow walnut Ikea Billy bookcases that can be with or without glass doors (available in 2 heights).

I need to see the whole space and IMO that YV meeds to either be mounted on an arm that allows it to be lowered for viewing or put somehwere else . So a bit of info as to the other spaces around this . for sure too.Why can you not change trim color ? Is that a real FP or electric ? IMO a weird place for a FP and for sure no room for bookcases to add to the clutter in that small space