Origin

In 2004 a Norwegian website called prikk.com started hosting a picture modestly titled “The main difference between Europe and USA”:

It was the only picture to be seen in a section called “Morsomme Bilder” (Funny pictures) and it featured an image split into two photos. On the right side, a supposedly American woman seen from behind and, on the left side, an European woman seen from behind.

As you can see by yourself, it is a picturesque way to mock on America’s obesity problem, in a manner not dissimilar from the tongue-in-cheek irony found with 3 Wolf Moon tshirt reviews

Spread

From 2004 to 2005, this funny picture travelled through several websites and gained minor popularity among European web, as can be seen by this Google Date Range Search. As demonstrated, in 2005 the general WWW caught on and the picture went increasingly viral.

A single instance of “Main Difference” was created on YTMND in 2005, and another was created in 2007. It’s far from a proper fad but does present evidence of the meme reaching the YTMND community:

• The Main Difference Between Europe and America by KensukeNol
• The Main Difference Between Capitalism and Communism

4chan: Battleground of Nationalism

Since the dawn of time it has been commonplace for citizens of one country to mock, criticize, and blame foreign countries and their shortcomings. This “Main Difference” picture was particularly provocative because words weren’t really needed; the two photos seem obvious and lead us to the “Europeans are better than Americans” conclusion, concerning health care, beauty and overall sexiness.

This makes for a easy trollbait and it is in this particular state of mind that it came to 4chan’s harbor.

On 4chan’s /b/, Trolls are anything but unusual. At least once a day since its creation there have been comparative threads between USA and Europe, as well as other topics, praising America’s power while making fun of Europe or, on the contrary, praising Europe’s power and criticizing America’s behavior. Any reason is enough to start a thread about wich country has the biggest… thing.

This picture added something more. It embodies the timeless rivalry between the two “blocks”.
It was, at first, a easy way to troll Americans because they are the majority of people going on 4chan. Then, it became a matter of time before someone made a template out of it:

Japan vs USA version:

As this 4chan archive shows, people started making their own version of the picture, being for one side or another, or picturing something completely out of context, thus funnier.

Tons of pictures were created from that point and “Europe vs USA” threads are still popping at least once a day on 4chan.