>>12930241instead of asking "what's unrealistic about this highly contrived and poorly analogous scenario I just made up", it's more useful to ask "what do we already know about that has effects similar to what I'm proposing".
We know that you can have epileptic seizures based on some repetitive inputs if you're predisposed to such. Drugs can alter neural function. Blunt force impact to the skull can cause physical damage to structures in the brain. There's dissociative seizures, which can cause involuntary behavior and sensation. Lesions in the brain can cause seizures. Physiological/medical causes like fainting or diabetic shock can do it.
There's lots of ways you can cause the brain to fuck up. Some of them work based on purely visual input. But none that we know of are anything like what your picture proposes, which is a priming of the human visual system for seizure based on an initial visual input. The closest I can think of would be something like a panic attack or remembrance of a triggering event related to PTSD - but that usually involves the initial event being traumatic or meaningful in some way, not a jpeg you look at once.
At the end of the day, I can't rule out something like the OP image, but based on the observed phenomena of the brain, it seems unlikely to me that it's possible.
