It is a picture of a "disk pack" which is a stack of platters (usually 14 inch diameter) in a removable set. The original hard drives were the size of a washing machine, and had these swap-able packs. They had a clear plastic cover with a handle in the center, much like a cake carrier. You plopped it on to the drive, turned the handle to remove the cover, and then closed a door over the pack to enable the drive.
Amazing that people no longer know what they looked like. I made a clock where the dial was one of these big platters on which the head had crashed, leaving concentric marks in the orange surface (iron oxide). Of course, I had to be different, so I used a 168 hour motor and the "clock" showed the days of the week. Those synchronous motors are probably long gone also. They used to run all the stop lights.