We're starting to notice an increasing number of users who are using special post images which are inserted into the top and bottom of every post they make.
Given that these images add nothing useful to the message, they are just decorative spam. We already allow massive signatures on CS for you to express yourself in, we simply don't have room for you to put images into every post as well.
If I see any more of these circulating I will begin warning the users who are putting them in - it is not 'on-topic' anywhere that it's used so it is spam.
It would also be spam to attach any other random images into every post you make - that's what a signature is for. If the image isn't specifically relevant to the topic you're responding to, then it doesn't belong in your post.
If you're not sure what I mean, then you're probably not doing it so don't worry about it.