^ exactly you can see the hole beam of light. and where it starts from.... they have a booth above where the movie is being played from and they have a little window up there so they can see the movie to make sure it is running ok and to watch over the crowd. thats why little gay kids who like to throw candy sit closest to the door/way in the back because the window is above them and the people can't see em.
NOTE: Throwing candy at people or at the screen in a movie theatre is not cool. never will be. infact it just makes the people who are actually watching the movie want to choke your head.... keep that in mind.