Alexander’s photography teacher is offering verbal critiques to each student’s latest photograph. He walks around the room and comments on each photo, saying, “Nice job with the elements in this image. I appreciate how all of the elements feel like they belong; there is a sense of visual coherence.” What design principle is Alexander’s teacher commenting on?

The design principle being commented on is unity. Unity refers to the coherence and connection between the elements in a design, making them appear to belong together and creating a cohesive overall composition. In this case, the teacher is expressing appreciation for how the elements in the photograph all work together harmoniously.