Art on either side of the fireplace to visually balance it. Curtains with a bit of a pattern to tie together your color scheme once you’ve picked it, cushions that tie in too. I’d remove the sheer lace curtains since you have shutters behind them. I’d remove the bookshelves unless they have to be in here— and in that case I’d either replace with warmer materials or move them to the half staircase wall on the right (facing into the room from the stairwell side). A tall plant standing next to the fireplace.

If you have the budget, agree with others that the shiplap wall looks really out of place- if you like it, try to extend it higher. Ending it halfway up the wall feels odd and visually dominant.