The theme sets the viewport
to device-width
. On an iPhone, that would be 320.
<meta name="viewport" content="width=device-width, initial-scale=1">
You'll want change the meta tag to the width of a full web site, for example, 1200...
<meta name="viewport" content="width=1200, initial-scale=1">
It should then render as if the window were 1200 wide.
Docs: https://developer.mozilla.org/en/docs/Mozilla/Mobile/Viewport_meta_tag