From what I know of the book, it was a critical success but did not resonate with the public the way Sinclair wanted it to. The government took notice and tried to better regulate the meat industry. Working people, however, were not drawn to it the way had hoped.
Altering photographs was part of Joseph Stalin's propaganda efforts to increase and create in the first place a personality cult for himself. He did this with the idea of creating and establishing the idea of himself as a great and important leader who cared for his country.
