I really think the tag when you see it should be converted to a pool.
The tagged images vary wildly from each other. They don't have a visual element in common, but only the criteria of "which may not be seen so easily or subtly hidden" and "[w]hen seen, it may come as a shock to the viewer".
These characteristics, including the relationship with a hypothetical viewer, are "poolworthy" material, comparable to "CANNOT UNSEE" and "Nightmare Fuel", albeit less disturbing than them.
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