This shouldn't have been put in "polls". Many won't see it here.

But....since it's here, the first thing I'd do is lose at least half of those pillows. They're bulking up a pretty set with clean lines.

Many thanks dear for the advice, please let me know whee should I replace the post, I'm still new here.

For the pillows I'm going to place only the two glittered. Any ideas about the blank opposite wall , I'm thinking to have some kind of fancy gypsum board, butt dunno in which shape! Any other ideas? Much appreciated

Here is an idea for those walls. Water walls are not only pleasing to the eye but they also help clean the air by attracting dust particles. Many different types available - see more at http://www.luxewaterwalls.com/fountains.html

Have you thought about installing some European/Contemporary cabinetry or shelving?

You have GORGEOUS high ceilings! Have you thought about bringing in some artistic lighting to fill that space?

I agree, some pillows should be removed. If you're thinking art, I'd pull colors from your pillows you're leaving. It would accent it well. Or maybe a gallery of some mirrors and/or pictures. You have tons of options for that beautiful blank canvas! :)
https://www.houzz.com/magazine/10-creative-ideas-for-eye-catching-walls-stsetivw-vs~24573405

A nice silver wallpaper to bright up the wall. It will make a nice contrast with your lovely sofas. (color)

the green of the solid colored pillows would really bring out the purple

High walls can afford the glamour of beautiful wallpaper. Add interest to the ceiling tray. Some wall and ceiling tray treatments to consider. Accessories you may like to match what you have.

Some rug ideas to complement your furniture