We know that when the eye sees, all the consequent information is transmitted to the brain by means of electrical vibrations in the channel of the optic nerve. [^1]
Our brains are remarkable at building associations. Surely, everyone has seen/heard something which caused another thought or image to appear in their head. However, you would generally not vocalize this new idea because you'd seem like a lunatic given how unrelated the thought is to the topic at hand.
By color-coding Japanese words based on their pitch accent patterns, one can infer how a word is read having never heard it before. After doing this enough, it becomes second nature to read a color-coded sentence and know exactly how it ought to sound. (Association of pitch to color)
Suppose you built some association of words/ideas based on color, and another set based on shapes, and another based on the space between shapes and colors. Would it be possible to encode large amounts of meaningful data this way that could easily be transmitted to a human in the same way a photograph would? This would be interesting not for any practical sense, but because it would require a brain to be wired in a way to process information in a completely different way than anyone else. Going further, what kind of bizarre ideas would randomly spring up in that persons mind just from viewing the world around them?
[^1]: V. Bush, “As We May Think,” The Atlantic, Jul-1945. Available: https://www.theatlantic.com/magazine/archive/1945/07/as-we-may-think/303881/.