Same here, also confused. I've only ever had Android phones (currently on Android 16) and I don't know what it means either. Pasting from the clipboard using a keyboard, an application action, or a context menu doesn't show a notification or toast. I tested it just now. The only system-level thing I see is a "Copied" toast, which is visible in the article's video.

Is this specific to particular Android versions or vendors? Curious if anyone can elaborate what we're supposed to see here.

edit: I will note that copying a password from a password manager showed it masked with asterisks in the keyboard's paste button.