Maybe you are interested in our Magento Lazy Image Loader which is totally compatible with SEO.
Improve the loading time of your site pages with our Magento 2 Lazy Load Product Image. Increase your site performance by loading product images as the user scrolls down the page. It helps you achieve better speed and performance, ensure a smooth user experience, better conversion and improved SEO score.
The following link Magento 2 Lazy Load Product Image would be useful.