The document discusses contextual broadcasting using mobile devices. It describes how media has traditionally been "boxed" and isolated, but mobile devices allow inserting context into media through location awareness and other sensors. This allows filtering content based on personal context like activities, social connections, environment, time, and more. The goal is to move from static boxed content to dynamic contextual services by combining a user's personal mobile context data with local sensor networks and global services. This would provide only relevant information to the user based on their unique context in that moment.