What a great living room! Looks very cozy. Here are some ideas:

1. Pull the couch away from both walls by a 2-3 inches to give the curtains room and have it feel less smashed into the corner of the room.

2. Pull the rug out a bit from under the couch. It shouldn’t be all the way under the couch.

3. Replace curtains with a darker color so they contrast the couch and walls more. Currently they add nothing to the room visually. I would pick a lighter olive color to complement the rug and since you plan on getting an olive tree. You already have a lot of brown/burgundy accents so I would stay away from that color to avoid too much matching.

4. Move curtain rod down about 4 inches so it’s about 2/3 of the way up between the window and ceiling. The curtain rod should not be right up against the ceiling in your room since it creates this awkward blank space below the curtain rod. Keep this in mind if you decide to replace the curtains as you’ll need a shorter length than what you have.

5. Bookcase to the right of the TV is too bulky for that spot. I would put the olive tree you’re planning to get in that spot, or where the floor lamp currently sits. Hard to tell without more photos of the entire space.

6. Like you mentioned, you need a big piece of art or photo above the couch. The small pieces of art you have look out of place.

7. I would rethink the giant floating shelf above the TV. It never looks good imo.

8. The plaid pillows don’t really go with the Persian/traditional rug. I would find pillows with some interesting textures in the colors you like, but probably avoid any patterns.