Windows detects media being played and shows you that inlay with controls. It must be detecting that stream somewhere being played, even if it isn't obviously playing in a browser tab. You should be able to control whether it shows media controls on the lock screen.
Maybe it included documents or correspondence from each of the 30 attempts? That would still be absurdly long at over 150 pages of documentation per attempt. But I could see them trying to make a point through the sheer volume of pages.