[mfukar]

As the paper [http://shattered.io/static/shattered.pdf] says:

> This is an identical-prefix collision attack, where a given prefix P is extended with two distinct near-collision block pairs such that they collide for any suffix S

The near-collision block pairs is the difference everyone can see in the image. Whoever created the PDFs did everyone the courtesy of keeping the suffix the same. There's numerous examples already of different PDFs with the same hash.