I and several others have mentioned LA Metro’s Every Lane a Bike Lane bicycle safety campaign. You’ve seen the graphic. Here’s how it looks on the back of a bus.
It reached me via a Santa Cruz County transportation planner, who got it from this page, who in turn got it from Michael Manio who originally posted it to the LA Bicycle Coalition Facebook page. (Thanks, Andy, for pointing that out).
If you go to the facebook link you gave, the poster seems to indicate it was his picture https://www.facebook.com/photo.php?fbid=10200176595835945&set=o.112820538777467&type=1&theater