I once read of a study in which a chimpanzee was tasked with sorting photographs based on the categories of the objects depicted and placed a photograph of a chimp on the pile of pictures of people.
So apparently at least some primates, unlike many other animals, can grasp the notion of a photograph. Here a western lowland gorilla at the Louisville Zoo seems interested by photographs on a cell phone, including images of other gorillas. In some shots the human and the gorilla appear to be sitting together, but there is glass separating them.
Probably half the people who have looked at this have thought of making a joke about Gorilla Glass.by