There has been a bleeding of photography to other media and a shift in the art world that views photography as a realist system of representation (ie., resemblance to reality) as a fading memory from yesteryear. Or as a fossil from a previous age when the relationship between the real and its representation, and truth and falsehood, defined the identity of photography.
That identity rested on the uniqueness of photography’s indexical relation to world it represented, a relation that was regarded fundamental to its operation as a system of representations. On the positivist account of photography, a photograph of something (a person) was held to be a proof of that person’s existence, and it was held that photography was inscribed by the things it represented.
In a digital world of the 21st century computer visualization means that photographic-style images can be made in which there is no direct referent to the world of objects and events. These digital images are less signs of reality than they are signs of signs. That means photography made with a camera as an image making instrument has the freedom to explore views or events without worrying about its identity, its boundaries or its relationship to other media.