Refers to a widely circulated (among fans, at least) photo of Trent Reznor (more commonly known by his performance moniker, Nine Inch Nails) outside of a train station in Ausfhart, Germany in 2008 while on tour there.
In the picture, Trent is seen stading in front of the 'Ausfhart' sign, pointing up at it with a very uncharictaristically comical look on his face, obviously amused by the sound of the word, pronounced "Owws-fart". Thus, the pic is now simply refered to as 'pointing Trent'.
just go to nin.com, lolnin.com, or go ask pretty much anybody on any of the forums at echoingthesound.org and they will 'point' you in the right direction to find this photo.
Apparently, pointing Trent has the sense of humor of a twelve-year-old boy...Who knew?