Reply To: Product gallery thumbnails load full size image

Hello,

In general, our theme is already optimized and doesn’t have too many resources to make your website slow.

Please check this manual for images configuration and site performance:
https://xtemos.com/wordpress-performance-optimization-the-ultimate-guide-in-2021/

You need to optimize images using a service like this: https://imagecompressor.com/ then upload images again. Alternatively, you can try to search for a plugin for this purpose to optimize directly in the site.

Best Regards.