Apple has apparently shipped all new iPhone 5s in boxes to carriers for approval and testing. Apple is as always using extremely careful techniques to prevent the details of the device to be leaked. As the Guardian points out, testing will be done in labs under high supervision.
Here is what the Guardian reports –
My carrier sources tell me that the boxes in which the new iPhone hardware is encased have been transported to carriers for testing. This is an important step in the release cycle for any phone. … The next iPhones go for their testing inside locked and sealed boxes so that the carriers can carry out checks on their network compatibility in their labs. It’s very high security, as you could guess; my understanding is that barely anyone inside the carriers gets to open those boxes, and even when they do the hardware is encased in a dummy body which means there’s no clue to what the actual phone will do.