In our multisite network each site under WordPress Websites has its own separate database tables. That means that images, files, and videos that you upload for your site are only available to you and will not appear in any other site’s media library.
Learn more about using the Media Library and Gallery by exploring the article below:
Media Library Screen
Learn more about displaying your images in a WordPress Gallery. These are easy to create on your site when using the “add media” option. The WP Tiles plugin will also help you create interesting layouts for your photos.