Man i was thinking…2 things actually
That flynn "cipher"
If triliteral, try here for decode https://www.dcode.fr/triliteral-cipher
If some reason its not (if it ever was), i would personally assume Q related so even though only 25 spaces, start the alphabet with+17 at the beginning and every row +17 letters to start
Id try with and without Q and see where the dark spots land. Similar to pic related minus the repeating. I imagine something along the lines of "where we go one, we go all" is the "hidden message"
My brother suggests "yeah could also be shifts with each representing number of shifts and location for characters" I believe in regards to anons keyboard shape