That's also how the GMail website still acts, which confuses me as well. Why can Facebook load a complex web app instantly while GMail still shows a loading bar on launch?
actually, when you load facebook, it shows an interstitial which looks like a page of posts, but is really just a bunch of blocks carefully arranged, and it has nothing to do with the final load page.
Huh. I checked back a few times. It looks like facebook loads an interstitial with boxes, that actually corresponds to the layout of the page, but not the content. This includes sentence layout (the boxes cover the area that gets replaced with text, similar for images). Now I'm curious what's going on.
