Try: site:facebook.com "Full Name" along with other known details. Sometimes cached or public posts appear.
If you share mutual friends, ask them to describe the profile picture or send you a screenshot (with permission). facebook private profile photo viewer v34 free extra quality
To summarize:
Some "viewers" are Chrome or Firefox extensions. Once installed, they request permissions to: Try: site:facebook
These extensions can then steal your Facebook session, post spam, or show you fraudulent ads. These extensions can then steal your Facebook session,