Privacy policy pop up in China

There is a new New Privacy Policy Requirements For Mobile Apps In China. One of rules is "They must be in a pop-up message, either on your landing or login page."

Can someone explain me why it has to be in pop up? Can a full screen be alternative? I guess they want make sure users stops everything else and their attention is focused on giving/not giving consent about their data. I am looking for official confirmation why it is has to be pop up, and can full screen be alternative which is law compliant.

I am designing for giant company which want/has to be fully law compliant.

Here is a link to the new requirements: https://www.appinchina.co/blog/new-privacy-policy-requirements-for-mobile-apps-in-china/