I would definitely make that area on the right a sitting or reading nook. You could make it a workout area or a coffee nook or a plant sanctuary if you want something different.

The wall on the right could be a board and batten style or shiplap to the ceiling. I'm guessing you are putting your headboard on that wall to the right of the window. This bedroom is huge!

Listing photos always make it difficult to judge the size of the space. What are the measurements for the nook area? I have some ideas - but I'm not sure how large the nook area actually is.

you can put decorative moulding on any style wall.

a pretty dressing table in the alcove.

You could use the nook area for lounging reading nook:

You could also add a morning bar/coffee bar/wine and coffee bar:

There are many different types of little "bar" areas that have been added to a primary bedroom - many are in the actual bedroom - not in a separate hall to the bathroom or closet area. I didn't see one in front of a window - but I didn't spend a ton of time looking + I'm sure that it could be done if you wanted.

If you are into plants, that area could be used as a pretty "garden nook" in your bedroom.

I have never needed a place to read a book in my bedroom and I read a lot. I would do plants in there they help with air quality and look awesome. No point is placing stuff you will never use in there at all. This is another example of bigger not better often. Not seeing the rest of thespace that is all I can offer . We put a coffe maker area in our guest room for practicality for guests who wake early it is great for them but usually never used even there .