I have followed the documented instructions to create the image import CSV, and produced an exact replica of the CSV shown, but with my own product details, obviously.
Then I follow the instructions for the actual import (http://docs.magento.com/m2/ce/user_guide/system/data-import.html), I choose "Products" entity type, and Import Behaviour "Add/Update", set the image file directory and then choose my CSV file.
When I click check data, it returns an error, saying:
1. Product Type is invalid or not supported in row(s): 2, 3, 4, 5, 6, 7. Checked rows: 13, checked entities: 13, invalid rows: 6, total errors: 6
Those rows do not contain a SKU as they are additional images for row 1 SKU, so have been left blank as per the instructions - quoted here:
If importing multiple images for a single sku, insert a blank row below the sku, and enter the additional image file names in the appropriate columns. The additional rows are understood to belong to the parent sku.
Can someone tell me if the instructions are out of date, and there is a working method to do this? Or if I have to do this some other way?
If it comes to it, I could manually add the additional product images to those products that need them, but would rather the automated method worked.