Stephen Schüz PRO said about 2 years ago on StimulusJS, Active Storage and DropzoneJS :
  Thanks for the great video and the simple setup! I've been banging my head against trying to display the photos that are already stored, when I open my form. I did something like this:
JSON.parse(this.filesTarget.dataset.urls).forEach((image) => {
  let mockFile = { name: `${image.name}`, size: 12345 };
  dropzone.displayExistingFile(mockFile, image.url);
})
The dataset gives me the external url (in this case on cloudinary), but I can't seem to use the displayExistingFile method w external urls... How would you go about displaying exising images in DZ?

P.S.
Maybe for a follow-up screencast: How to delete them again from the db?
And maybe as a bonus: Make them sortablejs?