It means profile picture

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed

Can be used as a short version of Profile picture

slang in the internet for Profile Picture. Short for pfp

An acronym that means picture for proof, largely used in text. pfp is a response to an action that someone "says" they are doing. Whether it is used online or in a text message. Most commonly used on status updates. Used to make sure that the person is not lying about what they are doing. After saying this the person should upload or send a picture to proof their statement.

Comparable with vfp - video for proof