The standards set forth in this Chapter shall not be construed to restrict or prohibit the following activities or products: expressive dance; plays, operas, musicals, or other dramatic works; classes, seminars, or lectures conducted for a scientific or educational purpose; printed materials or visual representations intended for educational or scientific purposes; women nursing infants; nudity within a locker room or other similar facility used for changing clothing in connection with athletic or exercise activities; nudity within a hospital, clinic, or other similar medical facility for health-related purposes; and all movies and videos that are rated G, PG, PG-13, NC-17, or R by the Motion Picture Association of America.