If you clicked a shared link and were sent directly to your Dropbox, you already had access to this file—the link has taken you directly to the file's location. This works for folders too. If you already have a folder in your Dropbox, its link will take you to the location of that folder.
This new feature gives you easier access to the files and folders you already have in your Dropbox. It also helps avoid creating multiple copies of the same file.
If you follow a link to a file or folder that is not already in your Dropbox, you will only see the specific file or folder that was shared.