This document summarizes Christopher Schmitt's presentation on adaptive images in responsive web design. It discusses using feature testing versus browser sniffing to determine the appropriate image to serve, including testing browser width, screen resolution, and bandwidth. It then covers various techniques for serving adaptive images, such as using .htaccess files, the <picture> element, srcset attributes, and JavaScript libraries. It emphasizes using a mobile-first approach and progressive enhancement to provide the best experience for all devices.