>>37157955It's all part of the janny memes.
Janitors of 4chan are often mocked, as they spend their time moderating one of the most autistic websites, without receiving any payment whatsoever.
People on various boards started posting pictures of dogs shitting, as the posters were metaphorically shitting on thr board and the janitor would have to clean the shit.
From there people started posting pictures of other animals or dogs drinking water, which is basically the same thing but less obvious.
