Example of a product page using Cover
Cover will fill all the available space with the photo and crop off anything that's beyond the defined parameters. Example is shown of what the original image would look like in a 1:1 ratio:
Example of a product page using Contain
Contain will make the whole image visible within the defined parameters and will add white space around the image if needed. Example is shown of what the original image would look like in a 1:1 ratio:
Portrait 2:3
Contain