What the console can hold, and who agreed to it
Per device: operating system and build, processor, memory and disk, battery, network interfaces and addresses, graphics adapters and displays, installed and running software, theme and locale, and the client version.
Two things keep that honest rather than creepy. Sharing is a single toggle the device owner sees in their own settings, and the console asks for a snapshot when it needs one instead of the endpoint streaming a live feed of a laptop. If the toggle is off, the request comes back with nothing. It is also a support tool: fixing a problem for somebody starts with knowing what they are running.