The 5 guys standing in the background probably would be "soldiers", but one has to remember that there is no police force in DPRK; that function is covered by the military. It, therefore, wouldn't be that unusual to see them at the airport.
I notice that Gabriel didn't take any shots of the aircraft. I would suspect if he did, that those "soldiers" would have soon jumped upon him. I have also been told by a person-in-the-know in Beijing, that taking photos on board the Air Koryo aircraft is also a no-no (but she is getting some to show me anyway).
Having talked to people who have flown on Chosonminhang/CAAK/Air Koryo, they have told me that the service they are given is better than they receive on "western" airlines; although there are no PTVs, inflight emails, etc. (well duh!)
Look at the photos below which are taken from older Chosonminhang (CAAK) postcards. With all these Russian aircraft lying around it would be like heaven on earth....well for me anyway.
Ilyushin Il-18s and Antonov An-24s in the far background
Notice that the pilots are dressed in what a bus driver in the "Third World" would be expected to wear...but worse
I had to laugh at the Coke on the food trolley...must have been taken on a flight carrying Kim Il-sung (who was well known to dabble in pleasures from the "west")