That picture is the first of a pair from this location in his second gallery (linked by someone here in the comments), and the description on reddit lines up with his comments on the slide:

In North Korea, there are places you can visit and places you cannot visit, and the latter are far more numerous. Well, this is one of them. Usually, we were accompanied by our guides, one in the front, one in the back. But at one point they were both in the front, which allowed for a literally 15-second long detour into this ordinary shop for North Koreans. That gave me maybe 10 seconds to take this and the following picture, before being kicked out by the bad cop, and the atmosphere became rather unpleasant. I'm not sure if he saw me taking these pictures.

He repeats that verbatim in one of the reddit comments, and adds "Also, I've got a photo album with the photos of my journey into North Korea, if anyone is interested." I don't really see that as the photographer trying to pass all the images off as special, he specifically linked this one image from that gallery, and clearly distinguishes between this image, and others from his trip. Whether this image is really special or not is another story, but I don't really doubt that the author believes it's special due to the circumstances he took it in (it could easily have been the guides trying to exert general control, not specifically that they viewed this location off-limits).

As another commenter here noted, it's possible he was sold an "experience" by the tour company he chose, and they were playing to the group. In any case, there's definitely a lot of popular mythology at play with regard to North Korea, intensified by the lack of useful information, and this all plays into that, which I'm sure it's one of the reasons it's gaining so much traction. People like the idea of him having to smuggle out the pictures, whether or not that's an accurate description of what happened or what he's really saying. I don't wonder at why it's being spread that way, even if I do lament it.

> As another commenter here noted, it's possible he was sold an "experience" by the tour company he chose, and they were playing to the group. In any case, there's definitely a lot of popular mythology at play with regard to North Korea, intensified by the lack of useful information, and this all plays into that, which I'm sure it's one of the reasons it's gaining so much traction. People like the idea of him having to smuggle out the pictures, whether or not that's an accurate description of what happened or what he's really saying. I don't wonder at why it's being spread that way, even if I do lament it.

I just had a chance to go through the second gallery and this is pretty much the same conclusion I have arrived at. A lot of information he tries to pass as facts are well-debunked myths that he swallowed hook, line and sinker.

Perhaps the word "agenda" is a little bit harsh, it feels more like ignorance/naivety than malice. After all, it is just another sad episode of regurgitated stale narrative being passed around as something novel.