On the iPad, are third-party app elements scaled up by PERCENTAGE or by ABSOLUTE height/width?

Clearly Apple has made new versions of its own apps for the bigger resolution of the iPad screen.

But most existing third-party iPhone apps will also work on iPad, so my question is whether those third-party apps will be scaled up simply by percentage (say, a menu bar that took up the top 10% of the iPhone screen will take up 10% of the iPad screen) or by absolute measurements (say, a menu bar that took up the top 200 pixels of the iPhone screen will take up the top 200 pixels of the iPad screen—so the main area, the content, of the app will be bigger on the iPad relative to its menu bar than it was on the iPhone). The latter sounds a lot more flexible and usable to me!