Any sort of device that involves AR or VR, such as smart glasses and virtual reality headsets.

Smart Glasses: Wearable glasses with screens with functionality similar to smartphones. Relevant for a short period in the early 2010s, then they died out. Of the ones that existed, most all appear to be Android or Linux based ARM systems.

the the device gives no indication of being in fastboot mode, just a blank screen

Surprisingly concise function, with a desktop, WiFi, audio, Bluetooth, etc. In essence, a computer mounted over one’s eyes.

https://wiki.postmarketos.org/wiki/Google_Glass_(Explorer_Edition)