These only last for one frame and they're gone. I've recently been watching breaking bad on Netflix and I've noticed sometimes that these "threads" just happen sometimes but I always think I'm going crazy. This time I caught one. But I can't screenshot it because Netflix prevents you from doing so. You'll just have to see for yourself. Breaking bad season 4 episode twelve around the ten minute mark. Immediately after gomez says "take a" when asking if he could take a look around in the bottom right corner of the screen. If you blink you'll miss it. What is that? It reminds me of fight club when Tyler explains the oval where they splice old film. Is there a technical name for these threads? Why does it happen? I didn't know where else to search. So I turn to the internet hive mind. Google is useless.