Not even a mysterious J.J. Abrams movie trailer can create this much speculation and bemusement. Last week, for no apparent reason whatsoever, Google changed its favicon from the uppercase “G” of its logo to its lowercase “g”. And the blogs have gone crazy. Which is probably the whole point of the change: Demonstrating how a minute change for the most ubiquitous web site can have enormous ripples. It’s like the ultimate chest thumping. They didn’t change the logo, they didn’t change the home page, they didn’t change the results page, they didn’t change the ooooooo’s. They just changed a sixteen-pixel square and created a stir. Now that’s branding.