name 1 other well known person who showing a benign picture of him causes a real risk of getting killed by his fans?
I've gotta say, I know quite a few Muslims and I can't think of one who would so much as take a swing at me for running around in a big t-shirt with Muhammad's face on it. Meanwhile, I can think of a few people who would take a swing at me if I was wearing, say, Osama Bin Laden.
Dream is [was?] a very popular Minecraft YouTuber/streamer, particularly among youths. He had been known for not revealing his face, and when he finally did, some parasocial megafans did not see the deified person they had hoped for and instead just saw a regular looking dude. Many non-fans also took advantage of this disparity and mocked his looks. There are [were?] probably some self-described Dream fanatics who would assume any real life picture of him is an affront to their parasocial deity.
The same parasocial elements could be assumed for lonely viewers of VTubers, if they are shown that the “man behind the curtain,” so to speak, does not line up with the fictional character that they are presented.