Hello,
If you use images with different size you can enable crop option in WooCommerce settings (WooCommerce > Settings > Products > Display) to make them equal height. Or you may try to add max-height for your image block, this is not good practice in general but if you want to have all the image block with the same size it can be like workaround for you. Please read more https://docs.woocommerce.com/document/adding-product-images-and-galleries/ https://docs.woocommerce.com/document/fixing-blurry-product-images/
Regards
