Designers often use visual materials as inspiration for their designs, by abstracting key features from the source of inspiration and then expressing them in another form. Shedding light on this distinctly human ability can contribute to our understanding of intelligent action, and inspire the development of artificial design agents. In this project, students learned about processes of abstraction by expressing real-world architecture using Lego bricks. A deep analysis of their design process suggests concrete directions for the future development of design agents, which may be able to utilize abstraction for automated design.