“Ghost Image” appears in mobile version of site

Hi there,

When looking at my site on a mobile phone, there is a large white space (that appears to be an image) that appears between my header and content area. On the desktop version it is fine until the window is made smaller (by dragging). I had my developer friend look at it and she thinks it is a theme issue. Any ideas?

The page I need help with: [log in to see the link]