How this works is that when you launch the app or move away from the app to another app, whenever you reopen the app, it will prompt users to unlock it using their face or fingerprint. Users will have the option of choosing how long they want to keep the app unlocked for, so if you want to multitask and switch back and forth often, then you can opt for a longer delay between security prompts.
However, it should be noted that Google does point out that there are some limitations to this. While for the most part it should prevent unauthorized users from accessing your files on your phone, notifications are protected and some Siri functions aren’t protected either, meaning that the new security features won’t offer up 100% security or privacy.
Google had actually introduced these security features a few years ago, but for some reason, the company later pulled it, so it’s good to see that it is back again. You will have to update to the latest version of the app if you want access to these new security features.