
Explanation

The text in the Policy Settings section of the exhibit explains what will happen.
If a user sends between 1 and 10 instances of the sensitive info (passport number), then a notification email and will be sent to the user and a policy tip will be displayed. The email will not be blocked though. Therefore, it will be allowed.
If a user sends more than 10 instances of the sensitive info (passport number), the email will be blocked and a high-severity alert generated. However, the user can override the block.
Reference:
https://docs.microsoft.com/en-us/office365/securitycompliance/data-loss-prevention-policies