Tom Clancy's Splinter Cell: Pandora Tomorrow HD

For every door which can be opened, hold down then you can opt to peep underneath the door by using your 'Optic Cable'. Whilst looking underneath, press then to toggle through the two visions which you have at your disposal. Do it on 13 doors and the trophy is yours, you can not repeat this process on the same door 13 times but you can do it on either side though only once.