How does Launcher get to choose which icon to display for different storage devices?

I have different drives; SSD, HDD, USB, eBook readers, and phones, usually show up with particular icon identifying the type of device.

I would like to understand how does Launcher or Nautilus get to differentiate storage device types and to assign a custom icon; if that's done at the application level, or is something at a lower OS level that may affect this.

I wonder if it is possible to set a specific icon to different partitions on the same drive, or to have a Kindle showing up with an icon that differentiates it from a normal pen-drive.