I think Susan Sontag is using the metaphor of Plato’s cave to depict the stationary role of photography in the modern day by proclaiming which images can influence the audience’s attention. It can potentially affect what we have already seen in the past and will directly influence what we would want to see in the future. Instead of feeling like the world is out of our reach by physical boundaries, photographs allow us to witness the world as a whole through our heads using memory and as a anthology. Being capable of viewing photos digitally via smartphones is the new way of collecting photos internally, a way to collect the world and actively share amongst people that we love and follow. In a sense, the confinements of the cave are being changed everyday with every new photo that is viewed through a gallery, digitally, or via printed substrate.
Interesting idea that the plethora of photographs in our world challenge the confinements of the cave. There is however a really important aspect of what Sontag is saying that you don’t address. She compares photographs to the shadows on the cave wall. They are inaccurate and misleading representations of the world. If so, what happens in a world where we base our knowledge of the world on photographs?