The app and the page would not be “connected” at all. Just an embedded view of the app on the same page as other information.
I could see a use case where inputs on the app may affect something on the web page it is embedded on, but that’s not the way I first envisioned it working. I suppose you could also have a Google Form on a webpage that would affect values in an embedded app so that the results are shown in realtime on the same page. Again, not my use case, but could see this as something it could be used for.