Youtube Video vs. The Universe

The video explains the vastness of the universe by comparing it to the size of Earth. It uses a 1920 by 1080 pixel video as a metaphor, where one white pixel represents Earth. The process involves scaling down the distance of pixels multiple times to illustrate the enormity of the universe, which is 100 quintillion times larger than Earth. The final comparison shows that the string of all pixels is 1/10th of the observable universe's diameter.

What does the tiny white pixel represent in the analogy?

What fraction of the diameter of the observable universe is represented by the string of pixels?