Floating cites, twisted plants, insects the likes of which have never been seen... The researches who successfully peered into the souls of gazers saw fantastical scenery that was quite unlike the reality they knew.
The researches began furiously detailing the sights of the netherworld they had never witnessed. However, they were not well received by the general public.
Apparently, society did not appreciate the subject matter and were worried that the researchers' depictions of the netherworld would only stoke certain peoples' desires to visit it.
Likely a coincidence, the human in the artwork looks like a younger version of the wizard, though he is unlikely to be the same character. However, if he is the same character, this would mean that not only the wizard was enough of a prodigy of magic at such a young age to get to the realm, in addition to being the only class to have more images, he could possibly have been the class to be in action the longest off screen.