Does this qualify as a bedroom?

[Bryan Cress]

I toured a duplex this week. 4bd and a 1 bd. The 1bd side had the bedroom off of the living room, but the walls only went about 10 or the 12 feet to the ceiling! I know... great ceiling height! It was clearly added in when this home was converted to a duplex. The room had a closet but no windows. Does this legally constitute a bedroom? If not, what issues might I run into renting and or on resale?