If I understand the question correctly, you're wondering what "hidden until reviewed" means?
Anyone can contribute to the brand directory (which you can find under Tools > Brand Directory), but new entries have to be reviewed to make sure there are no malicious links and that the information about the creator (the SLURL, the links to social media pages, etc.) are correct.
A trusted team does that for you (a big thank you to all the reviewers!); you cannot do that yourself (but you can apply to be on the reviewer team).
If you want to get an entry reviewed faster, feel free to write a message in the #brand-directory-issues channel in the "Get It Sorted" Discord group.
Please not that you can still assign unreviewed creators to your items. The links just won't be shown. But they will appear automatically as soon as the entry has been reviewed.