It looks like they ran Linux apps inside a virtual machine on an Android phone. That has been possible for a long time now. That is certainly a route Valve could go down, but it won’t be a very good user experience.
Steamworks SDK supports Android now. Obviously, should there be an official full Steam client for Android, the preferred route is for game developers to release native Android games with Steam integration.
https://www.androidauthority.com/run-desktop-linux-apps-on-android-how-to-3586539/
It looks like they ran Linux apps inside a virtual machine on an Android phone. That has been possible for a long time now. That is certainly a route Valve could go down, but it won’t be a very good user experience.
Steamworks SDK supports Android now. Obviously, should there be an official full Steam client for Android, the preferred route is for game developers to release native Android games with Steam integration.