That’s because the author, Peter Suber, doesn’t go beyond Nietzsche in his work (you can read his self summary elsewhere on the website). I’d suggest you read The Work of Art in the Age of its Mechanical Reproduction by Walter Benjamin[0], if you want an exposition on the power of the visual, and of shocks of experience, in the social and political world.

[0]https://web.mit.edu/allanmc/www/benjamin.pdf