No person operating a pocket billiard room or bowling alley in the city shall allow or permit any screens, curtains, blinds, partitions or other obstructions to be placed between the entrance of the room where billiards or pool is played and the back of the rear wall of the billiard room. A clear view of the entire interior from the entrance to the rear of the room shall be maintained at all times. No partitions forming rooms, stalls or other enclosures where the public congregates shall be permitted. This section shall not be construed to prohibit the maintenance of closets for storing purposes exclusively, or toilets.