Depending on your environment setup, some permitted users may have access to all files within a project.
The quickest way to allow other users to view your files is to share them upon upload. If you upload without sharing, other users will not be able to view the file(s).
You can grant view permissions to a file(s) in various ways, these include:
1. Sharing during upload to the project.
2. Sharing a file that has already been uploaded.
3. Linking or uploading a file to a ticket, which a user has permission to view.