How does it turn?
At first I was looking hard for a "Photoshop" trick, but in a couple of other videos on the same site I saw one of them sweep through a turn to make a pass for the next row. So, it does steer.
The rear wheels on the front tractor are straight axle ... it is just the back end of tractor. I guess the regular narrow front wheels are enough to get it pointed in the right direction?