Looks like the front tractor pulling the trailer cuts the base of the bine & twine (or the bases are pre-cut), while the second tractor somehow trims the top, laying it down in the trailer. Maybe the hops are then picked in a barn or something.
Milk jug with hole cut in side, apple juice added.This tip was in "Country" magazine years ago and is used to trap yellow jackets and hornets. The yellow jackets like the apple juice better than the grapes. Lures them right in and they can't get out.