That’s not a webview, it’s a separate api with fewer abilities. Custom tabs I believe.
You can see for example that it always opens as a fullscreen overlay in your app and that it always has that bottom or in your case top bar.

If that is true, how does the brain work?

Call everything you have ever experienced the finite dataset.
Constructing your brain from dna works in a timely manner.
Then training it does too, you get visibly smarter with time, so on a linear scale.