One Month Ago Facebook Came Up With Photo Viewer . 

In Revamped Photo Viewer , All Comments , Likes , Tags Were in The Right Side Bar And Photo Was in Left Side . Now Facebook Has Published Out New Photo Viewer . Which Allows Users to View Facebook Photos in Full Screen Mode .

FULL SCREEN MODE VIEW

That's It

And Now Use ESC Key For Exit Full Screen Mode

NOTE - New Full Screen Photo Viewer is Works only on Latest Version Of Google Chrome And Mozilla Firefox