My avatar is what it is to achieve a sense of contrast. My posts tend to be devoid of warmth, purely intended for cold intellectual precision. Also they tend to be quite intense. The baby bunny is ironic, but at the same time, it also represents a sense of mischief and destruction in disguise. Tiny little me? Rabbits are very destructive creatures, though they don't look it. My intent when I write is to destroy my own and other people's beliefs, and thereby create chaos, my preferred state. The "known" suffocates me because it is never perfect, I hate it, I feel this urge to annihilate it whenever I see it. Third, and lastly, I like the fact that the baby bunny is sticking its tongue out, 'cause it is defiant like that (even though it is just a little bunny). Overall, my avatar aims to make a far grander statement via utter antithesis than could ever be made otherwise. If I picked something else that is destructive, like a bomb going off, would it really say as much?
It's like that song "Here Comes Your Man" by the Pixies. It's this happy surf rock song about... the atomic bombing of Nagasaki. The ironically carefree melody is exactly what makes it so deadly powerful and moving.
At the same time, though, I do have this soft, playful side that is hidden in most of my posts.
My avatar used to be the gopher from Caddyshack, for similar reasons. I love the ironic destructiveness of cute little animals. Maybe there's something to it. I've been permabanned from the last 2 forums I frequented. I dunno what happens. I just post what I think to post, and I wind up setting everyone into a frenzy and then it's all over. Whatev I guess.
Do people sense the spirit of my avatar? I dunno. As for what I think about others' avatars, it is mostly unconscious, but I do feel they tend to accurately portray the intended message of whoever picked them. In the end, though, I don't think it has a very significant effect on how I think of a poster once I really get to know them and their habits. Just one small little part of their personality.