Cultural diversity

Even in a recently created bureaucracy cultural differences can emerge. Over the last year or so since the US Government decided that we all had to be finger printed and photographed I have observed an interesting pattern. Entering the US on the West Coast they insist you take your glasses off before they take the photo. In the East on the other hand you can leave them on. My final observation at San Francisco this morning confirmed this. I have now tested the theory in New York, Boston, Washington, Chicago, Los Angeles & Seattle as well as San Francisco. When I mention this different to the Immigration Officers they deny that there is any difference or generally indicate contempt for the other side. I wonder how this difference came about?