While the iPhone 4S is no longer the skinniest of the smartphone bunch, it's still pretty thin. Mind you, compared to an allegedly complete, leaked iPhone 5, the 4S looks positively chubby.
The images come from the guys who showed off the iPhone 5's battery, and while this is another pinch-of-salt moment, it looks pretty convincing. Anyway, throwing caution to the wind, It doesn't look all that thinner until you come down to a side-on view. Looking at the iPhone 5 alone, it looks like the
screen back is pretty much flush with the metal bezel, but the screen isn't, which is interesting in its non-symmetry.