Fog rolling down the river is what kind of phrase?

Read the passage from sugar changed the world. for an african, whether you were sent to the caribbean or south america, you were now part of the sugar machine. and it did not much matter where your ship landed. you could be working the fertile fields of brazil or the hills of jamaica; the brutal cycle of making sugar was much the same. how does the use of the word machine support the authors' claim in this passage? its negative connotation indicates that enslaved people had to work like robots instead of human beings. its negative denotation indicates that some people preferred handmade sugar over factory-produced sugar. its positive connotation indicates that plantations ran efficiently and produced huge amounts of sugar. its positive denotation indicates that it was easier for enslaved people to make sugar with machines.