Book excerpt: Molly Bang's brilliant, insightful, and accessible treatise is now revised and expanded for its 25th anniversary. Bang's powerful ideas—about how the visual composition of images works to engage the emotions, and how the elements of an artwork can give it the power to tell a story—remain unparalleled in their simplicity and genius. Why are diagonals dramatic? Why are curves calming? Why does red feel hot and blue feel cold? First published in 1991, Picture This has changed the way artists, illustrators, reviewers, critics, and readers look at and understand art.