It occurs to me that an interdicted Droyne world like Candory might in fact be an ideal location for this "motif of harmful sensation" thing, inasmuch as the world may harbor unknown Ancient artifacts and the harmful sensation in question might be something that is utterly innocuous to the Droyne.
That might be one of the reasons for the interdict, assuming the Imperials know about it, or - since the world is a Droyne world and they aren't affected by it - it's possible for the Imperial authorities to be completely ignorant of the phenomenon.
I might point out real-world examples, the seizure issue with certain recent films being one such. Also, there are a handful of folk - myself included - who experience very unpleasant vertigo effects from certain imagery. Seems to create a dissonance between what the brain sees going on and what the inner ear's reporting, which - since my inner ears have been known to argue with each other and are therefore not fully trusted by my unconscious mind - can result in headaches or violent nausea.
