As opposed to the Apple in Indiana?

I just picked up my Apple Pro optical mouse (for whatever reason) and saw that in the front curve on the bottom, right above the logo and just inside the rubber ring are the words: ‘Designed by Apple in California.’ This confuses the hell out of me. Was it put there in order to lead people away from the idea that someone ELSE designed it? And why is it specific to California? I’m just so confused… I wonder if someone knows any hardware designers over there and can ask them?