Design. Not just the back of the phone, the software as well. The position they've chosen to take is 'design minded android'. Despite the love/hate relationship with the glyph, that's what brought most, or arguably all, of the attention they have now. If they'd dropped the glyph with phone 2 and offered the same phone as it is now for a more reasonable price, this would've really been a bad move. All this is to say, it's never really meant to stand out in any other way.