These shadowy shapes (pink arrows) littered on the mountains are cloud shadows.
I just added a new method to our declouding algorithm that removes all cloud shadows for our next version of Cloudless Atlas. Now the only dark patches are things that ought to be dark, like dense scrubland in parks, and the shady sides of mountains:
I used this image for testing because it shows one of my favorite land features, the border of Lesotho and South Africa. South Africa’s agriculture industry is highly developed — for example, many decorative flowers that you buy in the Northern Hemisphere’s winter grow in this region. On the other hand, open land in Lesotho is mostly used for subsistence farming and livestock grazing. So we see Lesotho’s high, steep mountains in the bottom right of this image, a belt of tens of thousands of small farms and ranches running from bottom left to top right, and some of South Africa’s larger, more industrially managed fields peeking in at top left. At this resolution, land use differences make many national borders visible, but this is one of the most striking.
Hit me up on twitter (@vruba) if you have any questions.