Thank you for your update and especially for taking the time to create and share the video of your process; very helpful.
As I understand it, you are using WooCommerce and ACF for your site. You have defined an ACF repeater field, “Gallery Images” to hold several images of each WooCommerce product. I am not sure how your Gallery Images are connected to the WooCommerce “Product Image” and “Product Gallery”, but perhaps this does not matter regarding your question.
The video makes it clear that “Add Row” refers to the process of adding images to the ACF Gallery Images repeater field; that’s the part I did not understand in my earlier posts.
I regret that I do not see any way MLA can help you improve the process or let you add multiple rows to the ACF repeater field at one time. ACF is using the WordPress Media Manager Modal Window to select the row’s image. Maybe there is a way ACF can use the WordPress “Add Gallery” function to select and add multiple images at one time.
You should consider asking the ACF author if there is a way to accomplish your goal. I wish the news was better, but I am marking this topic resolved simply because I have answered your question to the best of my ability. I wish you every success with your application. Thanks for your understanding and your interest in MLA.