Ryne Dickens discusses the importance of designing websites for mobile devices. He notes that mobile usage is the fastest growing segment of the web and companies need to focus on mobile-first design. Dickens provides tips for making websites mobile-friendly, such as using responsive design, resizing images, and rethinking navigation. He shows examples of both a mobile-unfriendly site and a mobile-friendly site. Dickens emphasizes that mobile design is the future and companies need to make sure their sites work for mobile to stay relevant.