You probably found the weird pictos in Clair Obscur: Expedition 33 during the expedition festival by spending a token with Tom—it's a very unusual quest item that offers no clue what to do with it. However, considering you get them right before you set off for the continent, it's clear that you won't be using them in the city of Lumiere.
That leaves you with a bit of a quandary; you've got the whole rest of the game to explore but no clear indication of what this item is used for. If you want to skip the finding out phase, here's where to use the weird pictos in Clair Obscur: Expedition 33 and what they'll get you.
