Short version: It won't make a difference.
Long version: Some people habitually make long posts and say little. Some people habitually make long posts and say much, using every word they type for good effect. But in my experience nothing you say is going to change anything for either habitual long-post-writer. The best thing you can do about it is learn which people actually have something to say, read their posts and ignore the ones that you know just ramble on and on for no net effect.
And those pictures are called avatars. Some people have become very attached to their avatars, and it is recommended to avoid trying to dissuade them from using such. I happen to like that lynx in my avatar.