Thanks for making this as a feature. Before it is a feature, this was a comment from this other feature Pocket for Vivaldi where the aim is to keep links for further reading without making them as bookmarks.
The main ambiguity is that a note is first a text, that you can comment with image or link.
Or in this special case, you want to keep a link for further reading. That means, this is not a text, but a special link object that you can comment with text or an image. Maybe note should categorize two kinds of object explicitly or implicitly ? This subtlety becomes important when you have opened a page, that you haven't enough time for read it then : in this case, you want to keep this easily and quickly : in this case pinning tabs could mess uselessly tabs whereas a link not, but you need clearly and automaticaly stuff from the browser. I mean you click over a button, a submenu into tabs contextmenu, or simply you move tab object into notes, and a link note is made with link bold, with special icon to distinguish it from others notes or other links (that's why favicon is usefull).