I agree that the text and the picture of model do not appear to agree. It
is more efficient to just have one hydraulic arm (tractor) - and the text says it is a part of the platter.
That makes sense. It makes for a little more complicated platter, but over all, it would be less expensive to build.
I expect that for alignment, there is a camera directly above (and pointing straight down) the opening of each bay. This lets the platter align the path the car will take into or out of the bay.
The tractor arm probably remains narrow until it extends to behind the wheel of the car to be moved. Then it expands and places two rollers: one behind, and one in front of the tire of the car. Once alignment is confirmed, it starts pushing or pulling the car - to effect bay / platter ingress / egress (or vice-versa).
So the model could just show a flat floor, and show the tractor arm on the platter. Maybe someone in marketing thought the model looked boring.