Contrast in mediation throughout the duration of a documentary

I looked at 2 differing screenshots from SuperSize Me, and the ways the mediation differs throughout the documentary. Here, I note that the documentary changes in the amount of mediation it has throughout the duration, with the first example early in the documentary showing a large degree of mediation compared to the later scene which is further along the duration of the film. This shows that throughout a documentary, the amount of mediation is certainly liable to change.