In this update, titled
the “authorship update”, rich snippet results were reduced by 15%. On October
2013 Google announced that an update is coming (you can read about it here: http://searchengineland.com/matt-cutts-at-pubcon-174906) but it wasn’t until December 19th 2013 that
the update was in fact implemented.
Officially, Google stated that the update may take away the ability to display rich snippets from low quality content websites, but it seems that the actual percentage of removed results was significantly larger than 15%, with author photos almost completely disappearing from search results.