From the very first episode, Fringe would display weird looking photos when cutting to commercial. Frogs with Greek letters on their skin, apples with what looked like fetuses in the core, and hands with more than five fingers were part of this strange gallery. While they seemed to be nothing more than creepy x-ray-inspired art at first, more analytical fans noticed that the images and their order changed from episode to episode.
Eventually, the fans deduced that these little commercial bumpers actually produced a crude cipher with each unique glyph representing a letter in the English alphabet. These glyphs produced short word messages that were unique to each episode, often times having something to do with the episode itself or giving a clue to that week's story. This is just one of the many little mysteries that makes Fringe unique and helps the show engage its fan base even further.
