I was however under the impression that because I chose a responsive theme, that my site would conform to the shapes of other devices when I called it up.
This theme, similar to most responsive themes, “conforms” by resizing and rearranging the site’s elements depending on the device’s screen width. In this case the sidebar goes underneath the content when the screen width is less than 840px. These rules are declared on the file responsive.css.
If you want to turn this behavior off, go to
Frontier Options -> Misc then check Disable Responsive Layout