From what we are able to see, the side bezels are definitely thinner in nature compared to its outgoing predecessor, the iPhone 5s. Not only that, the glass on the 4.7” display is also widely believed to have been rounded into the edges, although this is not something that can be picked up from the pictures themselves.
There are also QR codes located on the flip side of each screen, which are useful when it comes to manufacturing and quality control. Apart from that, one can also check out the flex cables that are located near the top of the assemblies, as well as on the bottom of each assembly that holds a cut out which presumably is for the Touch ID fingerprint scanner.