>>16649584>frogpostersThese people are generally low IQ, and as such are unable to communicate with others very well verbally. Due to this, they feel lonely and isolated, and are searching for a sense of community, with low social risk (anonymously, so as to feel comfortable and not experience the pain of social rejection as strongly). So they post frogs as a kind of infantile call & response mechanism, to say "you hear me, right? I exist, right?" -- this kind of searching for validation. It's similar to a game of catch, where nothing of value is achieved but it's a better way to pass the time than doing nothing at all.
