On both Earth 1 and Earth 2, there is what appears to be braille writing on the walls of the Time Vault. It seems to have no functional purpose.
Why is there braille writing, or whatever the design is all over the walls?
To my knowledge, this has not been addressed at all in the show, but I have no idea if this is something from the comics.
Even if the designs are not braille, why are they there?