Made to block sunlight while letting a breeze flow through as a passive method to keep a space cool while providing a good deal of privacy. Depending on the application, they can also help to blur the line between the interior and exterior of a building.
These tend to be used more extensively in warmer climates. I first really took notice of breeze blocks used on some mid-century beach bungalows in Folly Beach, SC.
Ours is a single peace sign meant to be used as an accent piece. Perfect for the laid back vibe of Folly.