What is the application architecture for this Nomad / PhoneGap + Azure mobile services?

What is the application architecture for this Nomad / PhoneGap + Azure
mobile services?

This channel 9 video describes how to create a Javascript based
application in Visual Studio 2010, send it to a packaging service and get
the Android APK, (and iphone files, etc)
What is not explained at a sufficient level for me is how the application
architecture "works".
Authentication
I see that a variety of authentication sources are available, and they
ultimately pull from a web service of some kind. What is the data format
of the token (SAML, JSON, SWT etc) and
Data
What is the target of the authentication (WCF, something custom, etc?) and
how does it "collect" tweets?
What the client application pulling from? Is is using oData or a table
service?
Any other details on this implementation would be helpful.