After you are rescued from your initial encounter with the Man on Fire in the prologue, you must follow someone down a corridor. There's a rail to your left, which lets you pull yourself from the floor. Look closely at the cork board on the wall to see a poster referencing Kojima Productions and inviting you to "Join the Fox Team." There's also a booth number: CP 2308. That booth that was assigned to Kojima Productions during GDC 2013.