
Explanation:

Box 1: Notification to Microsoft Authenticator app
Do users have 14 days to register for Azure AD Multi-Factor Authentication?
Users have 14 days to register for MFA with the Microsoft Authenticator app from their smart phones, which begins from the first time they sign in after security defaults has been enabled. After 14 days have passed, the user won't be able to sign in until MFA registration is completed.
Box 2: 14
Azure AD Identity Protection will prompt your users to register the next time they sign in interactively and they'll have 14 days to complete registration. During this 14-day period, they can bypass registration if MFA isn't required as a condition, but at the end of the period they'll be required to register before they can complete the sign-in process.
Reference:
https://learn.microsoft.com/en-us/microsoft-365/solutions/empower-people-to-work-remotely-secure-sign-in
https://learn.microsoft.com/en-us/azure/active-directory/identity-protection/howto-identity-protection- configure-mfa-policy