Is there something around the corner past the closet and slider? Is this space in a traffic pattern? If so, you won't be able to put anything too bulky there. If you have a comfortable chair in another room that you can put here to get a feel for what size will work for you, move it to this space for a week to see how it appeals to you. The basics for a reading corner are a light, a small table and a comfortable chair. I would also add a rug.

In order to get better, more specific advice, we need more information. Take a picture of this space from further back so we can see how it fits in the adjacent space and answer the question about whether it's in a traffic pattern. How long is the wall that is perpendicular to the slider? Is there a balcony outside the slider?

I would start with a solar shade to actually see outside . Then a nice comfy chair , a lamp for nightime or clouday days and a table for cup of tea or glass of wine . Afor anymore help we will need context which says pics of the whole space for sure

Measurements would help.

And another MIA This is getting annoying we take time to answer but not one word from the OP and in this case no context .