Once upon a time there was a little webcomic called Ctrl+alt+del created by Tim Buckley. It was a simple gamer comic that had oodles of fans as well as detractors who disliked either the main character, the B^U-faced art style, or Buckley himself. This is not a unique thing for any creation/creator on the Internet, but Buckley made an easy target due to the Mary-sue qualities of his main character, his real life responses to criticisms, the fact that he pre-drew faces and body parts and just cobbled them together, and how a comic that was supposed to be funny was about as amusing as a Sunday paper comic strip ("not at all").
One day, though, Tim Buckley decided that he would introduce a bit of actual character development into the comic. The characters started becoming more responsible, and the main character and his girlfriend-- Ethan and Lilah, respectively-- got engaged. Lilah became pregnant.
This was an interesting way to take the story. Would the layabout Ethan make a good father? How would having a baby change the dynamics of the characters? Would people have some real growing up to do? Unfortunately, Buckley did this while still sticking to the 4 panel box comic format he'd had since 2002, which was an. . . interesting artistic decision. It is very difficult to have complex visual storytelling when you force yourself into the same four panels every time. It can be done-- there's no real "rules" in art or storytelling, after all-- but it takes skill and a deft hand to make the ultra-rigid structure work. Buckley had neither of those things.
However, the plot thread was ultimately fruitless as Buckley, in his infinite wisdom, gave Lilah a miscarriage in the now infamous "Loss" page, as seen here.
While I'm sure there were people somewhere who read this comic and felt the appropriate emotional response Buckley was aiming for, the rest of us saw that comic and went something like, "Hehe. . .what? Hehe-- what? Wait, What?!" before collapsing into disbelieving chortles. The response wasn't what Buckley had had in mind.
In the wake of the comic, dubbed "CADbortion," people quickly set about making loss edits-- direct parodies of the comic. This wasn't limited to just "the haters," but to other webcomic artists and internet personalities, like Cyanide and Happiness and Yahtzee Crowshaw of The Escapist.
However, a strange phenomenon began to happen within the meme. After a while people began noticing something odd; that even when reduced to nothing but basic shapes, they could recognize the Loss format. So utterly generic was Buckley's paneling that even in images entirely unrelated people could see the Loss characters. Once the phenomenon was noted, people immidiately began rearranging random things to fit the Loss format. The format is one vertical line, then two vertical lines, then two more vertical lines in the bottom left, and finally one vertical line with one horizontal line.
This is one of those patterned memes where, once you see it, you'll start noticing it everywhere.