Was wondering the same thing myself, found this article from late last year: https://techcrunch.com/2019/12/10/unsplash-for-brands/
TLDR: "working with companies to create branded photos, which will then appear on desirable searches."
TLDR: "working with companies to create branded photos, which will then appear on desirable searches."
E.g. https://unsplash.com/photos/GMLfxktwWcM or https://unsplash.com/photos/RtdjA55Su2k