The totem pedestal is converted into a holographic projector. It projects an image of the item the punch code represents.
This seems useful for previewing an item a code will produce, without spending the grist on it. You test it out with the blender card.
But it still renders the alchemiter unusable. At least without further upgrades.
Author commentary: This is a pretty clever hack by these two to get Dave the holopad. He doesn't have enough grist to make it, but Jade can just draw it to get the code, and then send the code to him. The jumper blocks don't need any grist to upgrade the alchemiter with those items, just a card with the code on it. Watching the kids figure out ways to hack the game is about as important to the story as watching them figure out how the game itself works in the first place. This is because the story is first about the game and the subversion of that game, and then about the narrative and the subversion of that narrative. So, long story short, this is why Dave can now see a completely useless hologram of a blender here.