From Charlie Crane's first book Welcome to Pyongyang. Behance describes it:
If there is no possibility of getting underneath the surface then the answer was to photograph the surface itself.
It took over a year for Charlie to get permission to go in with his camera: he was not allowed to take his mobile phone past customs and was met by two guides who were to accompany him at all times throughout his trip. At first they appeared robotic in conversation as if reading from a script, telling of their countrys great achievements. After a few days and many polaroids the guides became more relaxed and personable.
You can listen to an audio interview with North Korea expert Nick Bonner and Crane here.