How Do PowerPoint and Keynote Work in Mac OSX in Presentation Mode?

I'd like to understand exactly how PowerPoint for Mac and Keynote work in Presentation mode, from a code / MAC OS windowing standpoint. Both programs can enter presentation mode, which takes over the screen, but the mechanisms they use seem to be different. When I use mission control while running presentations, I see that neither open a new desktop (Space), which is what I might expect.

When PowerPoint is running and I press the mission control button, I see Dashboard and Desktop icons at the top of the window. The contents of the desktop icon show the presentation, and the main window shows the PowerPoint application not running a presentation. When I click the desktop icon or the PowerPoint application in the main window, mission control goes away and I'm seeing the presentation again, still in fullscreen mode. If I click some other application in the main window, like safari, the powerpoint presentation goes away and I see the desktop is back to normal, but if I then click on PowerPoint, the fullscreen presentation comes back.

Keynote acts differently. With keynote, in mission control I still see the dashboard and desktop icons, but the desktop icon shows the contents of the desktop without keynote or the keynote presentation. In the main window, I see the keynote application, with the contents on the running presentation.

I'm trying to understand how and why these programs act the way they do. Any advice on where to look or what to read would be appreciated!