how can you decide if a piece of art or photography can be classed as authentic? Whether it can be classed as unique? Digital dissemination is basically the notion that the constant reproduction of works is destroying their original authenticity. It used to be that the only place you could view a piece of artwork was in the gallery in which is was shown. No distractions, no reduced quality and no tiny sizing on google. You viewed it as it was meant to be viewed.
With the digital era however, this has dramatically changed. A picture can be seen in a million and one different places, all perfect replicas of the original. From books to the internet, there is probably not a single masterpiece that we have not seen somewhere or other, even if it was just flicking through a book. Post a photograph in twitter and it can be seen by thousands of people in a single instant. So, the idea is that this constant reproduction is destroying the authenticity of our work.