Interior Design is dependent on two concepts: beauty and functionality. While the former is subjective, the latter is not. Any given space or construction is built to be useful. Specifically, useful to people. How a person navigates a space, interacts with a space, or lives within a space dictates the success or failure of the designer's vision.
Architectural photographers illustrate this built environment utilizing specific camera angles, controlled lighting, and most importantly, by incorporating people in images.