Ultimately, the smallest unit of communication must be a representation of a cognitive thought. Pictures work for this, but words are more convenient. Generally

Ultimately, the smallest unit of communication must be a representation of a cognitive thought. Pictures work for this, but words are more convenient. Generally, you can't have a conversation with the link at the atomic unit because the link is only as good as what it links to; that is, the words or pictures in the link are what is added to the conversation, not just the link itself. Also, it would be really confusing to communicate in links as there would be a difficulty in providing context.