>>528185831
First off anon, you are severely autistic. That's fine, but recognize that your sensibilities do not match up with the common populace.
There is a common fan headcanon where bocchi is a futa with a massive cock. The illustration you posted is by Khyle, who is well known for sus memes:
https://twitter.com/khyleri/media
This website is 4chan, which has fostered a reaction image culture since its inception. Because Bocchi has a tendency to make a lot of funny faces and there are many different artists on the internet creating fanart of Bocchi, Bocchi naturally becomes a prime character to use for common generic reactions, similar to cats and frogs.