This sentence is comparing the public to pigs without using words like "as" or "like", which would make it a simile, most likely. In this case, since there's no such use of the mentioned words, this fits into the definition of a metaphor:
<em>"a figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable."</em>
She began to write a few years after the death of her mother. Chopin's work was influenced by her observations of the world around her, and boy, that world was full of conflict. She watched the emergence of the feminist movement, which had a big effect on her work