This recommendation was made after input from our privacy law section regarding the role of online service providers such as search engines and social media websites, which may not have any monitoring of material that is posted or retrieved through their services. So where there is no knowledge, no mens rea on the issue of consent, of whether dissemination of an image was consensual or not, there should be no criminal liability.
However, there are websites that exist for the purpose of revenge porn or other non-consensual dissemination of images. Those websites would likely meet one of the bases of culpability, those being solicits, counsels, incites, or invites—probably invites—and would thus be parties to the offence.