Place the photos you use for your profile and cover images in a gallery that is set to unlisted. (Unlisted is controlled by the Visibility setting in your gallery.) It will show up when you are logged in but it will not show for your visitors.
Anyone with the Link (Unlisted): Hidden from the Public
Galleries visible by Anyone with the Link can’t be seen by the general public on your SmugMug site and aren't crawled by search engines. The only way someone can view them is if you (the site owner) give them a direct link. When you do that, it'll look something like this: //www.smugmug.com/gallery/n-Z8xhv
It's a good habit to look at your site in one browser while you are logged in and in another when you are logged out. That will allow you to work on your site but to also see it as your visitors will see it.
Comments
Place the photos you use for your profile and cover images in a gallery that is set to unlisted. (Unlisted is controlled by the Visibility setting in your gallery.) It will show up when you are logged in but it will not show for your visitors.
From the help page Gallery, page, and folder privacy settings:
It's a good habit to look at your site in one browser while you are logged in and in another when you are logged out. That will allow you to work on your site but to also see it as your visitors will see it.
Musings & ramblings at https://denisegoldberg.blogspot.com