That red decal, which appears to be 2006, is the same color as the currently legal 2011 red color sticker. That some of the red was accidentally peeled away exposing the yellow one behind it made me look close to see why some was missing. Poor technique I guess.
Some people collect the whole set of colored registration stickers
http://justacarguy.blogspot.com/2010/01/unusual-way-to-display-registration.html