This is getting a little abstract.
But it appears to economize on space. Now all you have to do is stick a card in a slot to apply an upgrade. Don't have to bother with the shunts anymore.
Author commentary: Think about this for a second. The card Dave just inserted in order to collapse the whole structure like that? That card is still in there. One of those four yellow cards is the one for the jumper block extension. Which means if you take the card out, that huge thing instantly reappears. Try to picture Dave doing that. If he pulled the card out, the jumper block would rocket out of the side of the alchemiter like a huge cash register opening. It would probably launch him off the roof of the building.