I think I would paint it the green that is in your rug. Then I like the two pictures you have and would put them side by side, about 4 to 6 inches high. Finish off your decor, with two tallish lamps and it will would look nice. IMO.

I would do something layered, like this:

I like the blue color better than the yellow. Repeat the color in your pillows and accessories...

To help make the fireplace the vocal point of the room and look more like a fireplace I would add stone above. You could do this by using peel and stick tile that looks like painted brick or stone or even peel and stick wallpaper. Then add a large horizontal print or artwork. This will help define the design direction of the room and give it a vocal point.

What about TV? May be nice mirror above?

I think you should give it a fresh coat of black paint and find artwork that compliments it....

Thank you for all the suggestions. What I like best is using artwork that has black in it so that it talks to the soapstone fireplace. The visuals helped so much.

Hang your two pictures vertically on the wall right of the fireplace and recess. Center them 5' above the floor, one hand's width apart. On the wall where the bedroom dresser and little mirror are, you need a larger piece of casegoods to visually counter balance the fireplace opposite. An etagere filled with decor items might be nice. Then paint the recess above the fireplace black to match it. Get a nice piece of wall sculpture to hang on the black wall. If metal, match it and the picture frames. Or hang a very large mirror there to reflect the decor on the piece of casegoods.

I think you’ve got a lot of different and competing patterns going on in your space…..I would reduce that, then look at it again before deciding on art.

i like the mantel idea. if i were to paint it i would go with a maroon red. pulling out the color from your rug.

Lots of colors going on in this room. IMO you've got to curate this room a bit to make it more cohesive, but I think you already know that. Not sure how you decided the greenish/blue rug was the right choice for the room but here are options if you decide to paint the wall above the fireplace a color before you select the art.

This wall picks up the color of the chairs

This wall picks up the color of the rug

This color picks up the color of the sofa

This color extends the color of the stone.

This is the current wall color.

Seeing the modern glass chandelier, I like a modern feel, though doesn't have to be a grouping of organic shapes and branches.

Do you have any soft black framed pieces of art?

Marari Bone Distressed Texture Wallpaper, Sample · 詳細

York Peel and Stick Wallpaper Soothing Mists Scenic Blue/Beige PSW1098RL Simply · 詳細

But your rug, etc. doesn't seem toward modern so much. I don't often like mirrors above, but it could be an eclectic addition -

Glamorous black and gold fans stun against a cream background in this luxurious wallpaper. Its layered design has a dimensional effect and will add an Art Deco flair

Ruhlmann Cream Fan Wallpaper Bolt · 詳細

This seems in vibe with pillow, chairs, maybe the rug... I wonder if there's an era/history to this, like your unicorn pillow has, but idk about it...

Anemone Multicolor Floral Wallpaper Bolt · 詳細

Thousands of options, but this has the salmon type color and lines like the railing and chandelier....

you could buy chair covers?

Surya Quartz QTZ-5010 Area Rug, Orange/Brown, 8'x10' Rectangle · 詳細

Reminds me of Craftsman...

Mandala Decor Mix Ceramic Wall Tile · 詳細

even to experiment -

https://www.amazon.com/dp/B08Z492MZR?tag=amz-mkt-edg-us-20&ascsubtag=1ba00-01000-a0029-win10-other-nomod-us000-pcomp-feature-rscomp-feature-rscomp&ref=aa_rscomp&th=1

I think your art is fine. I would paint the section of wall the color in your rug. Just add some pottery.

You have a great eclectic decor style, I really like it. I think your idea of wallpaper is a good one. Love that last one @everdebz posted.

This Holli Zollinger one is pricey, but I wanted to show another example of colors/pattern. I like how it coordinates with your chairs.

It has black in it, too:

Anyway, not neccessrily that one, but I think wallpaper would make it such a great feature wall, with interest and movement.

Grouping of wicker mirrors. (Excuse the bad mock-up.):

More ornate, has a family heirloom quality, collected look:

If you did a mirror or mirrors, I’d replace the one over the chest with art.

Or keep it simple:

Paint it and add a large piece of art that has some black in it. Not sure I love the idea of patterned wallpaper, but the peel and stick kind is easy enough to remove when you’re tired of it.

I want to thank Everyone for their contributions. Now I have lots of good ideas.

Installing shiplap above your fireplace would add more interest and would relate both to the wood in your ceiling as well as the board feature in the fireplace surround. It would be a nice backdrop to your prints and compliment your cottage like colors used in your kitchen and area rug. A few ways to stretch those prints along that long wall would be to give it some friends by either finding two complimentary smaller prints to place in between or adding a pair of decorative candle wall sconces on either side, or functional electrical ones if added lighting is needed. You could also balance the two prints placed together by adding a large (tall) lantern on one side and a trailing plant in a comparable sized footed planter.

Lots of good ideas here, but it doesn’t change one fact, in my humble opinion (which some others share, it seems): the OP needs to reduce the many patterns and styles in her space…there are too many different pillows, chairs, rugs, all heavily patterned etc, already. She needs to find some cohesion here, narrow things down to a style and color group; at this point, adding more pattern and color with accent walls and wallpaper, pictures etc won’t really improve things. Reduce and pare down first, THEN add new elements…it’ll be worth it.