Thank you for sharing, Steganography is the most important element in this puzzle (more than cryptography and complicated calculations), the problem with those characters and symbols is that they are highly subjective which means that you can see something that the others can't see or see it in a different way and vise versa.
I agree that there has to be something visual to find. Reflecting on the old MAD Magazine folding images and the many references to mirrors and perspective I have read by people who may or may not be privy to the true solution, I made a few attempts at manipulating the image to see if anything popped out.
I put together an album. I included some descriptions in the captions. Please take a look and see if anything jumps out at you.
https://imgur.com/a/aJgyj