That's a VHS cassete on the right! Can you imagine the size of that "floppy disk"? It was an unsuccessful format of rewritable Laserdiscs in early 1980's. The article also says that early PC CD-ROMs were in caddies too.
There are many disc-in-a caddy formats that originated from Sony: 3.5" floppies, minidiscs, early Blu-ray prototypes that later turned into PDD, PSP's UMD... Have I missed something?