The reader.

Always a good time to open a book...

Perhaps it's someone who feels trapped in their own home in a block of apartments and makes these "escapes" to read their book in a space that allows them to dream of other worlds.

Now that I've taken a closer look at the image, I can see that the reader is inside a medieval military fortification.
These fortifications were used to defend against invaders and provide refuge for local populations. Now the "invader" is different, but so many centuries later it is still doing its job.