Had to study that a while, yea, the big fan sucked up from the head, through the fan, blew into the cone, and heads dropped down into the combine throat. Sure looks like it didn't feed the cyclinder evenly, but perhaps the volume was pretty low...
The little fan on the side blew into the tubes for an air header, to blow the grass into the cutter bar.
My take on it?
That is some work on there! Glad to see the pics.