Changing focus a little, consider for a minute the area and border around the org chart. This is its canvas, a drawing area reserved for building the chart. This is the space within which the org chart must stay, so that the chart readjusts itself accordingly each time you add a shape to it.
The effect is that you'll see shapes and text get a little smaller as you add more to the chart. You'll later be able to adjust the chart size through scaling and using the Fit Text button on the Org Chart toolbar.