Only paid plans allow you to post adult content such as images. This is the case because we can not be responsible for the use of adult content in the Free version. If we detect adult content in a website running on the Free plan, we may shut down your site without notification.
We take this seriously since it can bring us a lot of problems. Paid plans are responsible for their own content, and everything is allowed. We will not be responsible for anything posted on your paid plan.