While the whole build is impressive, the most clever part involves a 3 1/2″ floppy disk that hides an SD card and works like a regular USB flash drive when inserted into the floppy drive.
Floppy disks, once a common storage solution ... a sound card was pretty much a necessity a few decades ago. Sound cards were often plugged into PCIe slots and provided additional audio jacks ...
Most of us may have gratefully abandoned the floppy disk a decade or more since, but even today many PCs and their operating systems retain the ability to deal with these data storage relics.