It's about being close to someone but also having a distance to them and being professional about your job. It's not an easy task and you can't just put someone by your side as Justin Bieber himself realized (his own words, after having a friend who may have looked intimidating, but did not have experience in dealing with a really large crowd of fans).
But Bieber is not the only one in this, there are also other people who get their time. There is also the music when there is no narration (good job by Kim Coates, an actor you may know from Sons of Anarchy, other TV shows or movies), which may irritate some people. Also the fact that we also delve into war zones, might not be what some may expect. But whatever jumps this may seem to make to things you didn't expect, it also gets us into the mindset of a bodyguard. But even there, you have different approaches. Not everything can be covered, but a lot is. Really enticing if you are interested