What I love about the spaces that are truly “hidey holes” is the sense of your interaction with the space somehow being different from your interaction with its surroundings. This gives it a sense of being elsewhere - perfect for reading and being transported to another place, time, and identity. In this case, the difference comes from the small space, the “out of the way” aspect, and the fact that it’s functionally on the floor.
Also, that rug!