Shelves, mirror, artwork--many choices are available.

Love the aqua and cream and silver - would a black and white photo work here? I am not sure of your tastes but love the silver accents and would like to link them with a long panoramic picture. Look at yellowkorner for some great ideas.

A black and white photo would look great! Or a long mirror or even a picture of the beach.

I would say a very large, bold abstract expressionist print or painting along the lines of Franz Kline. (At least the width of middle of chair to middle of chair.)

Either that or a huge mirror to open up the space. Mirrors can be like windows that make rooms seem much larger, open and fresh.

Either way, don't be afraid to go big!

Definitely some art, I think. Though not seeing the whole room..... as stated ⤴ above, shelves with some pretty silver toned and sparkling glass accessories, etc., might add to the nice look you have so far. The color looks very serene. Good luck! :)