The Glyphs, sometimes referred to as wind glyphs, are graffiti found on a wall of the maintenance shed near the lighthouse. Max Caulfield can comment that they remind her of the wind in "Chrysalis". Interestingly, they don't appear during the two visions Max had near the lighthouse.
The glyphs can seem mysterious at first but are actually a reference to the novel La Horde du Contrevent ("The WindWalkers" in English) written by Alain Damasio - one of the Dontnod co-founders - where each symbol designates one of the "Member of the Horde" and each paragraph of the book starts with one of the symbols, telling the reader who the narrator is for this part.
While it would be possible to translate each symbol to find a deeper meaning related to the Life is Strange's characters, there actually is a very logical explanation for the glyphs.
In the novel, several tactical formations to withstand wind are mentioned such as the diamond, the bow... The water drop formation (formation de contre en goutte d'eau) probably served as an inspiration for the developers (it is featured at the very beginning of the novel). It is likely they slightly reorganized the symbols to make it look like a triangle instead of a water drop. It can be assumed a triangle made more sense in the Life is Strange universe since the Eye of Providence is featured quite prominently in the game and its prequel. At the end of the first episode, the graffiti signification hadn't been established, so it's possible these glyphs were as much a red-herring as a reference.
- The lighthouse is probably one of the windiest areas of Arcadia Bay so the wind-related glyphs have probably been put there on purpose.