These have actually been around for centuries, and were first used in Venice for protection from the sun, and in the Carribean to protect homes from intense wind and heat. They are sometimes referred to as hurricane shutters. The window devices can be installed on cabanas, gazebos, verandas, and on commercial locations for style and aesthetic-appeal.
The unique design of the shutter makes it effective in what it was meant to do - keep the sun and elements out. It can also provide privacy from neighbors and let a cool breeze come into the building.