This is a demo of double-factor authentication on scratch. You will need to log on to this project with the same username on 2 seperate devices. On one you will click the Begin button. Then, on your other device, a notification will pop up saying you need to authenticate your other device. If you click the "Authenticate" button, your first device will be authenticated.
Double-factor authentication is used in settings where a lot of privacy is needed, like in big companies. However, it doesn't really serve a purpose in Scratch because you can just click See Inside and view everything. This is just a demo on how it COULD work.