You’re right, good catch! The reason is we don’t consider Unsplash to be a conventional stock photo repo, since the style and quality of photography digresses so much from the usual stock photo sites. We probably should have pointed out what we meant by stock photo- the article is targetting sites such as Shutterstock, iStock, Dreamstime, and the like. We love Unsplash, it has a very personal twist on similar subjects, making the photos available there that much more relatable and honest.