It requires you to print the piece with the loop side down. Then you have to pause the print to insert a 45x55x0.5mm shim into the void in the loop in order for the magnet ring of the attachment to hold it in place. (see photo of example in Prusa Slicer)
The author remixed this model.
This piece fits on top of the base of the stand (with a 12mm M4 screw instead of the regular 8mm) and allows for the storage of a different attachment rather than the diffuser. If you don't have curly/wavy hair, this might be desirable.