All About the Little Green Glob
Subject:   The empty strip
Date:   2002-08-26 04:23:22
From:   synaesthesia
"The difference is subtle, but one that is important to me as a user. The difference is the presence of a thin (approximately 10 pixels) empty strip below the window. The default frame treats this area as off-limits, just like the dock and the menu bar. The utility of this is that we have a convenient spot to click through the windows or the desktop in the background."

It strikes me that making sure that part of the desktop is visible so that it can be clicked on to switch to the Finder is a hangover from OS 9 days. It is no longer necessary, since the Dock, which already reserves screen estate, has an icon which will achieve the same.