Section 91. Whenever eggs which have been in cold storage are sold at wholesale or retail, or offered or exposed for sale, the basket, box or other container in which the eggs are placed shall be marked plainly and conspicuously with the words ''cold storage eggs'', or there shall be attached to such container a placard or sign having on it the said words. If eggs which have been in cold storage are sold at retail or offered or exposed for sale without a container, or placed upon a counter or elsewhere, a sign or placard, having the words ''cold storage eggs'' plainly and conspicuously marked upon it, shall be displayed among, upon or immediately above the said eggs. The display of the words ''cold storage eggs'' shall be in letters not less than one inch in height, except that the container in which eggs sold at retail are delivered to the customer may be marked in letters less than one inch in height if uncondensed gothic type is used, but such letters shall in no case be less than one half inch in height. All markings required by this section shall be done in a manner approved by the commissioner of public health. Whoever violates this section shall be punished by a fine of not less than ten nor more than five hundred dollars.