This is meant to be a fun replacement for the more standard and boring 32-byte binary keyfiles. Here you can generate an image that has the same security as those files but something you can also open in your image viewer.
Some encryption software supports keyfiles to enhancing their security. This includes DM-Crypt/LUKS, OpenZFS, VeraCrypt, TrueCrypt, KeePass, KeePassXC, and others.
So long as the file is unique and sufficiently secure to be used as a secret cryptographic key, it'll work. So why not have some fun with it?
Below is a random selection of 36 Password Runes from 60 double-sided tiles. See this security analysis for more details.