>>codeth+QR
It's still a custom ROM and it's not uncommon for those to be reskinned in interesting or weird ways. Plus, their website already uses the outline of a phone with their logo inside of it, why not make that a screenshot of their ROM with their logo as a background?
Furthermore, I'm interested in what their solution for email, calendars, and all the other Google services look like. If it's AOSP, that's a good reason not to use this ROM. I suspect it's not actually using AOSP's apps, though.