What is a "ceiling pocket"?

A ceiling pocket refers to an architectural design element that creates variations in ceiling height, often recessed or indented areas. This feature can add visual interest and depth to a space, serving both aesthetic and functional purposes. For example, a ceiling pocket can be designed to conceal mechanical elements such as ductwork or provide a space for ambient lighting, enhancing the overall design of the room.

The other options do not capture the essence of what a ceiling pocket is. While air circulation and lighting fixtures might be related features within a space, they do not define a ceiling pocket. Similarly, a flat ceiling design refers to a uniform ceiling without the dimensional changes typical of a pocket. Thus, the choice highlighting varying ceiling heights is the most accurate representation of a ceiling pocket.