The Product image gallery portion of the Products Theme settings control the appearance and layout for the Product page images.
Adjust the image container's aspect ratio
Select a Gallery aspect ratio that best suits the orientation of your product image. To get the best results, product images should be consistent in dimensions.
These settings only control the appearance of the product image for the Product page. To adjust the same settings for the product grid (e.g. Collection page), refer to this article: Products: Product grid
Using an uncropped setting will generate white space around the image to create a uniform grid without cropping your image. The background in the editor indicates the applied white space, but will not appear on your storefront.
Arrange the layout of the thumbnail images
The thumbnail images are the additional images for the product framed in smaller containers outside the main image. These can be positioned either below the main image or beside it on the left.
Select an option from the Gallery thumbnails position to arrange these images.