The Harvester retained a few of what Elaina saw back when it was still a rusty abandoned component found on the ground. It looks like a large rake without the pole to hold one, and is too big to be used practically by a person. Not only that, but it looks like a rusty maw at first glance.
However, the Harvester that her brother is showing is no longer the same. The two maws that were like two sets of teeth from top and bottom have been separated from one another and are attached by a swirling component. It seems to spin and seems to "rake" in anything it passes by. The "teeth" of the harvester are not sharp but thinned, and no longer look dangerous like before. The spinning component is then attached to another metal component that Elaina can't see the insides of. However, it extends towards the back of the tractor where another attachment was placed, and the location of the seats is indicated for the Feys.