It is the illustration of a face of an unknown male person that is located on the northern slope of Mount Chiliad near the cable car station. The face itself is drawn on a rock edge and appears to have been spray painted.
Upon closer inspection, the face bears a stunning resemblance to the face of Jesse Pinkman, one of the protagonists of the American television drama Breaking Bad. However, some players theorize that the face is simply that of a game developer. The strange easter egg has no purpose in the game's storyline. In the Enhanced version of GTA V, face is replaced by cock and it may suggest, that Rockstar thinks, that the man is cock.
Although the easter egg is located on Mount Chiliad, it doesn't connect in any way to the Mount Chiliad Mystery.