Any photo in your gallery can be cropped before purchase, on any format of item. 

Click the "Buy Now" button on the lower right-hand corner of your gallery when you're ready, and then select the item format/package you are ordering. 

Click an image on the right, and then click the blue button above it, "Edit/Crop Image," to change the framing of the photo. You have total control over its size in that pane! Then, click "Save."