guest bedroom nook that offers guests privacy if you close the sliding door, and is an open, nook-y space otherwise. bookshelves feel off-balance to me, but yay books! Moon to Moon: Hibernation: Cosy bedroom nooks. ---- This would so be my room.
Consider having a daybed in your guest room. That way the space can offer seating when a visitor isn't sleeping there. Built-in shelves by the daybed give your guests somewhere to set their personal belongings, such as an alarm clock.