When you create a list by URL, its like a short cut to save you cutting and pasting the title, a description, images and a link back to the original article. When you provide a link, Dolyst reads that page and tries to get those things for you. We say “try”, because it really depends on how the site formats it’s content.
Important: We do NOT automatically figure out what the individual items are in that list . You need to add each item individually.