If you need to see a profile picture in better quality for legitimate reasons (e.g., verifying a business or a new friend request), use these safer methods:
When a user activates the Profile Picture Guard , Facebook prevents direct downloads and full-screen viewing for non-friends to protect against misuse.
The picture guard is supposed to protect the profile picture from downloading and saving. It is to protect it from regular trolls,
The term often refers to third-party websites or browser extensions that claim to bypass Facebook's privacy locks. However, official "verification" for these tools does not exist from Meta (Facebook).