It's amazing to see how "off" those other designs look. It's almost as though the finalized design is the way the phone "should" be and every other design is a failure.
It seems like great design is really just a product of discovering how a product should naturally take shape, rather than dictating style. I think this is what separates Apple's product designs from everyone else.
I saw a few other designs that reminded me of other versions. It made me wonder whether this 4S design, for example, was the original intent, but engineering restrictions at the time did not allow for this execution. Will we be seeing future iPhone designs resembling one of these?
It looks to me like that early 4-style prototype has much thicker glass on the front and back. I'm pretty sure it took Apple and their manufacturers a while to figure out how to the super-thin glass of the current phones.
It seems like great design is really just a product of discovering how a product should naturally take shape, rather than dictating style. I think this is what separates Apple's product designs from everyone else.