Gimme a break
C'mon, SDAI-Tech1, you're really stretching it. I have to believe you know what a metaphor is.
Masturbation is a common metaphor for a non-productive (literally, "non-reproductive") activity. For example: "Bowser's just jerking off if he thinks he can get through to the Righties".
"Circle jerk" extends the metaphor to the group activity of mutual "pleasuring" through mutual self-congratulation. E.g., "...yet another circle-jerk of Rightists congratulating each other on their good taste and inherent superiority because of their shared beliefs".
Get it?
--Robert