When you import product images into Shopify you can specify a URL for the new images. In most cases Shopify is able to download these images directly but in some situations this fails and no product images get imported. We've noticed this with Dropbox images hosted on the dl.dropboxusercontent.com domain.
We've added a work-around to this in the app so now any Dropbox images should import correctly, even if they're from the dl.dropboxusercontent.com domain.
Learn import about importing products to Shopify.
