Zoomed Banner Image on Mobile

Hi,

I am having trouble with the mobile view of my website and hoping someone can help. On an iPhone, the banner image is zoomed in to an unflattering piece of our school ceiling. This is not a problem on Android, or on the square space mobile preview. The issue occurs on every page of atrium.org.

What it looks like (iPhone):

What it should look like (Android):

Any suggestions are much appreciated – thanks!