How to create bulk galleries
Please note that the Bulk Galleries add-on is in beta and may not work perfectly at this time.
Create a new gallery with the default settings you want to use for all the new galleries to be created.
Create a new folder (whatever name you want) in the “wp-content/uploads/sunshine/” folder on your web hosting server. You can upload a hierarchical structure of folders with images in each respective folder or just the image files themselves into the newly created folder on the server.
Sunshine will create galleries based on the hierarchy you create with your image files/folders.
Go to Galleries > Bulk add new. Select the respective options. Optionally upload a .csv file which will override any default settings for the new galleries you are creating. You can download a sample .csv file from this screen in your WordPress admin.
The galleries will be created and images copied to each gallery.