Eureka!

No one seems to have noticed it, so I will draw your attention to the pattern at the bottom of the page which has replaced the panoramic view from my old office. If you scroll down to the bottom of the page, underneath the Earth Advisory Board notice, the WWW Deprication classification, and my home connection speed, you will notice a pattern consisting of white and blue squares.

Who can tell me:
1) What does this pattern represent?
2) Why is one square a darker blue than the others?
3) If you were to stumble upon this tile pattern on a wall, what would you expect to find behind the mis-colored blue tile?