Collaboration and editing not just happen on the page, often you need to co-operate with your project team for the documents, reports, pictures, tables. Whether targeted marketing plan or a complete project plan, you can make your project team members in Confluence to provide feedback on your document and let you be able to work in tandem.
Share a file
In a page, you might have a lot of files, but you only want your project team members to provide feedback only for a file of them. You simply need to file feedback to share your project team.
And ways to share the same page:
- Click on a thumbnail or link to preview the file.
- Select Share (Share) button.
- Enter an email address, user name or user group name, and then click Add after you send a message.
Your team members will get your mail and your message, and file sharing links to view shared files.
Share notification will only be sent via e-mail, this notification does not appear cartridge (workbox) 
in.
https://www.cwiki.us/display/CONF6ZH/Share+and+Comment+on+Files