In the past, if orders were fulfilled by a lab, the customer would have always needed to crop the image to exactly match the geometry of the product that they were ordering.
However, with the new no crop option, a full-size image will be generated, uncropped, into a new image that matches the geometry of the print the customer wants to purchase. This means that you can sell any image on any print size as long as the image uploaded has enough pixels to be printed at that size. It no longer needs to match the aspect ratio of the image to the aspect ratio of the product.
For ease, we have automatically enabled this feature.