Studying the anatomy of a design can be very important. It's really good for analyzing what works in a design and what kind of messages can be picked up easier than others. When you have a message to give an audience the designer should do research to seek out the best ways the audience can understand. Each part of a composition should connect to the central idea trying to be conveyed. Many different messages can be put together to create an even stronger mood.
If something comes up in design such as using a shadow, it's going to be used again because it's effective. Designers used ideas from things people are already familiar with.