I found a paper that mentions this photograph https://www.researchgate.net/publication/348506390_Return_to_the_Native_Earth_Historical_Analysis_of_Foreign_Influences_on_Traditional_Architecture_in_Burkina_Faso/download

The photo was taken by Walter Mittelholzer and is the “figure 6” referenced in this quote:

“In terms of urban planning, the two cultural worlds also clashed due to their completely opposing approaches. The classic European order, designed and based on the grid as an urban design tool, was diametrically opposed to the spontaneous and organic order of local groupings. The current great city of Ouagadougou, which was then composed of clusters of houses and the first facilities, was already beginning to adapt to this new foreign planning. The impressive photographs taken by Swiss pilot Walter Mittelholzer during his flight over the city in 1930 left valuable evidence of the time when the two orders coexisted (Figures 5 and 6). However, this coexistence was not to last long since, as can be seen in the images, it was to be the fabric of the new French planning that would finally prevail in city development.”

So basically, France said “you have to build your cities on a grid now” and the local Mossi people interpreted that their own way