These are cozy and exclusive design windows manufactured from many small squares.
They open outwards. An outward sash presses harder against the frame in case of strong winds. This is why these windows are very popular in Scandinavian countries, where marine climate is prevailing.
In Lithuania these windows are used to preserve the antique style of the buildings, e.g., in log, frame houses and rural homesteads, in houses built or renovated in cultural heritage territories.