The video above is a special DVD of Kamen Rider W was released bundled with the August issue of Televi-kun Magazine. It basically tells the viewers regarding Kamen Rider W's Gaia Memories.
In the Kamen Rider W Televi-kun Special DVD, Philip temporarily looses his memory regarding the Gaia Memories and Kamen Rider W. With the help of Shotaro, he manages to search for the answers in the Planet Bookshelves.
Source: JEFusion