This diagram use the three dimensions visual.
We see three dimensional images in everyday’s life. When people could not draw three-dimentions long times ago, they used to use perspective in the plane. What is the reason? As you can see classical painting, if there is no perspective people have a confusion to understand picture. In other words, the reason expressing three dimensional images is to raise people with reality to understand it more easily. If you use three dimensional images to diagram, it would be effective way to deliver it for people.
This diagram just saw the new stadium diagram for the ALM features (Visual Studio “Team System”) in Visual Studio 2010 and Team Foundation Server 2010.