The library plugin uses the extension points of the Studio library to extend some basic features of it and to add some new ones.
The image gallery creation dialog allows the user to create a new gallery document from an image selection. The images selected in the library are shown as thumbnails in the dialog when the 'Create Image Gallery' button is pressed. After the creation of the gallery, these images are automatically assigned to the list property of the document.
The library plugin uses the library list view extension point to show some additional columns in the list view/search results. Additional columns are a site column, where the site name of a content item is displayed and a preview column, where images are shown as thumbnails. If the content item itself is not an image item, a referenced image is shown, such as the first picture of a gallery.