Art forms give humans a higher satisfaction in emotional release than simply managing emotions on their own. Art allows people to have a cathartic release of pent-up emotions either by creating work or by witnessing and pseudo-experiencing what they see in front of them.
I think in this quote, Zeus is referring to the fire as the "evil thing in which they may take pleasure to their gut," because he refers to it right before he uses the word evil to describe it.
Some characteristics include being more artificial, with exaggerated proportions, and distorted perspectives. Mannerism took influences from the high renaissance period.
