Those round flat things on the arm are blades that are super sharp. The operator is cutting the tops of the grapefruit trees off. They keep the trees a certain height and width so that they are easier to care for. Note all the tree debris on the windshield. I have no idea how the guy running that could see where he was going.
The side trimmer (a different machine) hasn't shown up yet but that thing is even worse with gigantic blades that trim these trees so that they're almost square.
I think Stephen King could have a ball watching these machines and thinking up new stories.
