How to customize mobile pages on twenty twelve?

Hi,

I’m developing a child theme for a customer based on twenty twelve. When I test it with my PC browser, all works fine. But when I test it in a mobile device (like iPod touch) I get a different page. For example, the footer is not changed, instead it shows a “view full site” link that links to the site with my child theme changes.

I tried to find how to identify the code for these mobile pages, but no success so far. Is there something that I’m missing. Usually I just override the pages like header.php and footer.php in my child theme. Is there anything I need to override these pages in the mobile version, and how is the mobile version detected by the theme?

Thanks
Marian