Thanks you guys
The back elevator is for a second set of hooks. The point at which we shot this video we didn't have these hooks on yet. The way we have it set up now is so the side you saw in the video is for picking 4 totes one right after another, the other side however has 6 hooks phased with the handles of the totes and allows us to move a stack of 6 totes with a container on top.