Your app will have a default style which all controls will use unless you override it. In the above example, the first label is showing the default style. The other controls have custom styles. If this does not yet look like a native iOS app, know that these are all native controls. Most iOS apps have navigation bars and tabpanels which we have not yet implemented. But those are certainly on the schedule for the first release that includes iOS support.
It's important that we get the style support right because eventually web and desktop apps will use the same style API we develop for iOS. Put another way, we are designing a style API for iOS with the desktop, the web and iOS in mind.