The manual is relatively straight forward, it shows 3 vendor-API extensions to OpenCL, OpenGL, and DirectX which allows the programmer to create files on the GPU. AMD markets this GPU as being able to play 8k video or perhaps do some kind of huge memory computation (without ever being bottlenecked by the PCIe bus).
EDIT: There's a second, shorter "device driver" manual which shows how the card works. Apparently, there are 4 NVMe SSDs on board the GPU.
http://pro.radeon.com/_downloads/SSG_Driver_Installer_Guide....