Some users wish to "watch" individual attachments, and be notified of changes, without having to watch an entire page.

For example, on a collaborative page that houses ten attachments, a user watching the page would be notified any time any of the ten attachments are changed, as well as any time the core page itself is modified. But all the user wants is to keep track of attachment A and be notified of its changes.

The question was posed on Atlassian Answers, and the recommendation was to set up an RSS to track the labels of the attachments. This is not quite going to achieve what we are looking for.

https://answers.atlassian.com/questions/134973/is-it-possible-to-watch-an-individual-attachment-rather-than-an-entire-page