It is an internet meme in which corporates both infamous memester Pow Koudoin and Joey's famous catch phrase (from F.R.I.E.N.D.S) "How you doin". Originally in this meme people send eachother "Pk6" randomly (to confuse their friends) and post the results on reddit. The 6 stands for F.R.I.E.N.D.S 6th episode it is used. Now it's gotten so far that people now use it as a greeting and a enquiry about people's feelings.

A cultural and aesthetic mind-state that prioritizes making money, even as an “underground” or “radical” creator. The work isn’t made for money, but it’s the money that matters the most.

It means "How you doin" but is supposed to be thought of how Joey from F.R.I.E.N.D.S would say it.