Pictures!

That is, pictures on the wall, ie artwork.

Plant(s)! :)

Ha ha ED.
Looks lovely so far. Perhaps a large piece of artwork behind your sofa.
Are you happy with the wall colour? A dark blue on the TV wall would make TV less of a feature /focal point. Or you could have a TV gallery wall but might be too busy for your style?

I think your space could do with some colourful wall hangings to add some interest and colour. Your room looks lovely but your colours are muted.

Some pics

i want to add either wall paper or artwork but i cant figure out on which wall, the TV wall or the one behind the couch... which colours should i go for in that case

oh and i have a free space between the couch and the door. can't figure out what could b added

Add a Ficus or palm where the vase currently stands. And perhaps some smaller plants (socculents for example) next to the tv. And some artwork, personally I prefer one or two larger pieces over several small ones (though grouped smaller ones count as one).

I think it needs height-think standard lamp, shelves, pictures, oversized house plan and ceiling pendant lights.
It’s also possible you need to add different light sources to give atmosphere at night- consider under furniture lights and softly diffused eye level lighting.

Your positive is its such a neutral scheme you could go for a bold accent wall to give it a bit of personality either on both walls or just the TV wall. You could then add a gallery of pictures around the tv as suggested above and layer lamps, plants to give it some interest. . You can always replace the navy cushions to tone in with the accent wall.

grey accent wall brown furniture - Google Search · More Info

grey accent wall brown furniture - Google Search · More Info

grey couch navy wall brown accents - Google Search · More Info

thank u all for your comments and advices!!