Shitlifting is a form of mental masturbation, where one talks themself up by talking shit without backing it up with actions. It is a form of stroking ones own ego through words.
Words are cheap, don't say a word, it would only be for validation or shitlifting ones self ownership anyways.
In some stores you cannot go to the bathroom without paying a man/woman who is standing in front of public bathroom area. Shitlifting is the act of not paying the man/woman who is standing in front of the public bathroom and taking a shit.
"Dude, are you seeing that? I think that guy is shitlifting!" "Ooohh man, that guy is going to jail!"