When you Hide gallery, it removes the gallery from the thumbnail navigation. A hidden gallery is therefore not be visible anymore in the gallery index (or as a sub-gallery of its parent).

Note that if you include a hidden gallery to the navigation menu, it will in effect become visible to casual visitors, regardless of this setting.

The Include images in public search option lets you control whether to include a gallery's content in the public search on your website and on search engines (e.g. Google). (Search within the hidden gallery will always be possible).

See also