By what metric does Spotify decide whether a device is a phone or tablet? Granted, the line between "tablets" and "phones" has been blurred for years, and there is no universally agreed upon distinction. 

However, I am curious what metric Spotify uses to decide whether to call a device a phone or a tablet.

Most people would call my OnePlus 7 Pro a "phone", yet Spotify identifies it as a tablet:



What metric is used here? And why?
Found this answer in a Spotify Community post:

Free account on a tablet only allowing shuffle play
Solution

Spotify classes a tablet as anything 7 inches or greater. Anything under this will only have shuffle play in a free account.

Spotify needs to identify each tablet using its ID in the build.prop of your tablet. If you are using a lesser known tablet it may be that it has not been matched in the database. Please contact support using the contact form here and let them know your device model, Android version and display size stating that you only have access to shuffle play.



Source: Spotify Community - Spotify doesn't recognize device as tablet