Enable crop to images or upload images with the similar ration. 

http://rehubdocs.wpsoul.com/docs/rehub-theme/shop-options-woo-edd/image-sizes-for-shop-pages/

On my website I am able to get the images right. The pixel etc. are the same as all the other images. The product image is not the same as te rest of the images. See attachement.

Your help is welcome to fix this.