It says "all private parts must be fully covered". An ass should count as a private part. The description says that not only porn, but sexually suggestive images are banned, and I can't imagine how Andrew's posts are not sexually suggestive. And even if it isn't, the only times nudity is allowed are artistic and educational posts. While some posts from Andrew are artistic, there are some that aren't, which excludes all the reasons it should be allowed.