Many corporate laptops display in 1366 x 768 pixel resolution, as do many budget models purchased from discount stores. The low vertical display height triggers media queries in some Squarespace templates causing banner images to display in a slimmer format that normal. You may not want those slimmer banner images, and you can override the behavior with a bit of CSS.
Note: The specific examples that follow apply to the Bedford template. The general technique however, should be valid for most templates that include banner images in their design.
Recently I was contacted by a designer working on a Mac who had just learned that his clients were displeased at seeing skinny banner images from their Windows machines. Using my own site as an example, the designer saw images such as in Figure 1, whereas the clients saw much slimmer images such as in Figure 2.