Would there be a difference, if Apple had downloaded the content and was serving it from its own hosts? (As far as an app user is concerned, there isn't much of a difference.) Now add to this the hosting fees / resources used…
This would actually cross the line. Right now there's a strong argument that Shortcuts is just acting as an images-only web browser, (like Lynx, but the opposite). If Apple actually copied the images to their own servers then they're copying the author's work without his authorization.
