I was recently given a second monitor at work. I now have two huge monitors on my desk. This greatly alters my perspective of the world outside my window. Before, I could see some activity down in the parking lot below. Now, I can only see the top edges of the buildings, the tops of the trees, and the clouds in the sky.
The people below, out in the parking lot, who are walking up to the building; when they look up at my window, all they see is my crotch - and the backs of two big monitors.