Gatsby V2 introduces significant changes to its layout system, moving away from the automatic application of layout components in favor of a more explicit, React-style approach. This shift aims to reduce complexity and mystery bugs by requiring developers to manually import and use layout components, thereby enhancing code transparency and simplifying data flow between layouts and pages. The update also includes faster hot reloading, the ability to add GraphQL queries to any component with StaticQuery, and improved CSS handling for better performance. These enhancements are part of a broader effort to make app development with Gatsby more intuitive and enjoyable, as reflected in the V2 migration guide and additional new features.