If You Watch X Backwards, It's About Y is a snowclone template often seen on online message boards, to change the narrative of a popular films using reverse chronology. It is used to highlight the hilarious or ridiculous aspects of the movie or comment on traditional cinematic and narrative conventions.
One of the earliest instances of flipping a movie's narrative appeared on the SomethingAwful forums on May 20th, 2006 and linked on the Discarded Lies forum on May 21st, 2006. The original post re-imagined Star Wars, Titanic, The Lord of the Rings, Batman Begins and Carry on Camping.
Several months later, on January 3rd, 2007, the trope appeared in a question on Yahoo! Answers. That June, YouTuber Bigshot210 uploaded an edited montage of Jaws arranged in reverse chronology. The description was nearly word for word from the Yahoo! Answers question, reading: "The story of a shark who throws-up humans until they open the beach." The video has since been removed due to a copyright claim by NBC Universal.
On February 20th, 2009, Redditor sixdoublefive321 posted a thread using the Jaws line as the topic. Several people in the comments began posting their own versions of the snowclone and the thread eventually amassed over 3500 points overall. That year, more threads appeared on the Call of Duty forums, the xkcd forums, and 4chan's /b/ (random) board and /v/ (video games) board. Blogs including Unreality Magazine and Popped Culture also posted about the snowclone.
In 2010, threads appeared on The Escapist and Reddit. A third Reddit thread was posted on February 26th, 2011, eliciting additional instances. If You Watch X Backwards images and text posts were featured on Mental Floss, Laughing Squid, Buzzfeed, Funny or Die, Pop Hangover and the Atlantic in March 2011.
In early 2011, several single topic blogs were launched to curate similar jokes in both image macros and text posts, including IYWIB.com, If You Watch It Backwards and Watch It Backwards on Tumblr, as well as @IfYouWatchItBackwards on Twitter.
Search for "If you watch X backwards" spiked in March 2011, the same month the single topic blog was created.