Ice milk, when sold in package or wrapper, shall be labeled in plain legible type, not less than eight point, with the words "Ice Milk." This shall not include the containers used when ice milk is drawn in front of the customers’ eyes. A sign on a white card with letters not less than four inches in height and two inches in width containing the words "Ice Milk Sold Here" shall be posted by the vendor in a conspicuous place in the salesroom in every establishment where ice milk is sold, except that the sign shall not be required in those establishments selling only ice-milk items in packages or wrappers, each item of which is labeled in plain legible letters, not less than eight point type, with the words "Ice Milk."