When you are taken over with emotions clear thinking is dimmed. Process of decision taking is endangered. Screen exercise helps detach yourself emotionally from the current situation and settle in clear thinking. Here you have to imagine what another person would do in your situation. This will help you to evaluate the problem more clearly.
If we close our eyes and think on the current situation causing stress, we project a picture on the screen of our mind as if it were a film. You have to imagine what really happened and not what might happen. After some time you will be relieved of stress.