Some art on the walls. A chair with colorful upholstery. Window treatments. Plants (real)

I agree you could add a nice chair, if it would be practical and useful; and adding art is a great suggestion, too, plus more plants is always a nice boost - maybe on a slim bench in front of window, as in image below. ( definitely doesn’t have to be this many, though. :))

Other than that, you could also do things with lighting and/or paint. Really just depends on how far you’d like to go with it. Lighting can often make a big difference in a space. https://www.overstock.com/guides/home-office-lighting-ideas

That big cabinet doesn't look very useful. I'd replace it with a credenza along the back wall. Pull the desk toward the camera to gain space for it. Can you replace the carpet, get a nice new upholstered chair, and add a floor lamp by it and a table lamp on the desk? Drapes will soften the look a lot.

These are great ideas . I don’t really need a chair there though . The cabinet is used to keep our religious items for praying and it has to be in that direction according to our culture . It doesn’t have to be that cabinet but it’s functional.

Attaching few more photos

Nothing wrong with your current cabinet, and of course the current cabinet placement is non-negotiable

If you can, I would suggest changing the flush mount ceiling light to a more interesting flush mount, semi-flush mount, or a lower hanging chandelier - and for sure use a fixture that is dimmable. Also, if you are able to put a mirror on the wall that faces the window(s), the mirror would reflect the windows, and would also reflect a chandelier, if you hang one. This could provide a major change in the look and feel of the space.

I included info for items I used in visual below, too; and if you like any of them, you can search the product by name to see if they are also available from other vendors at more competitive pricing, etc. These are not intended to replace the suggested items I posted above - but are just some additional ideas for you. Of course all the items I have posted are just suggestions.

Great. I never thought about having a mirror there . I will
Look into these products

Thank you so much

My pleasure.

I would go with wall art instead a mirror.

There was a wall art on that wall before and that was a world map. I can keep that back on the wall.

Try rotating the desk so that the chair faces the camera.

I have thought about that too, but all the plug points are on the wall that the L is currently hiding. It would just expose all of them I believe although I have to tried. Are L shaped desks always supposed to be adjacent to the wall?

You might try turning the desk so it faces towards where you were taking the photo. Then you can add some artwork on the wall behind where he will sit. We also might recommend some window treatments, other chairs in the room, and a nice chandelier or other lighting options. Below are some ideas from home offices we have designed.

Weston Bauhaus · More Info

Alloy Penthouse · More Info