Where you live has no bearing on the photograph Martin. Same as having had to climb a mountain and nearly freezing to death to take a pic of a pretty sunset has on the pic of that sunset The viewer doesn't care.
Have to agree with Martin here...
Riaan, your example here just does not stack up since the photographer freezing to death is NOT the subject of the image (unless that was what was shot, of course!)
However, the minibuses in Martin's image are the express subject of the image, and given the non-universal implications of those vehicles on a road in urban South Africa as opposed to the same vehicles on a road in Europe or North America, an explanation is definitely in order.
The fact is that as a South African I don't need the explanation, but everyone else would...