I think Frank nailed it.

Check my attachment for the evidence...

My KML file uses both a ScreenOverlay to superimpose the MSNBC photo on the base imagery, and some <Region> magic to fade the view in and out. For more details on how to do this:

http://earth.google.com/kml/kml_21tutorial.html#workingregions
http://earth.google.com/kml/kml_tags_21.html#screenoverlay