Hello,
Also, about size of product images read here – https://xstore.helpscoutdocs.com/article/89-product-images
https://woocommerce.com/document/fixing-blurry-product-images/
It is recommended to use a graphics editor and prepare product images (make them the same size) before uploading images to your media gallery.
Also, it would be better to disable “Stretch product images option” option via Theme Options and re-upload images that are “too small” in large resolution.
Regards