On the labels of imitation milk products the use of pictures and symbols depicting dairy or agricultural activities, or associating the product with such activities, and use of dairy or agricultural terms or words, or derivations or cognates thereof, shall be subject to restriction or prohibition by the director by regulation. The basis for such regulations shall be the degree to which such symbols or words make or fail to make a significant contribution to a truthful and complete representation of the product, or appear to be likely to be deceptive and misleading to the purchaser.