The Directory theme is highly responsive. It is designed specially to perform well in devices of any resolution. Therefore the maps in the directory theme has to be responsive too.
The Directory WordPress theme comes with responsive maps that auto-adjust the width according to the device they are viewed in, the height is adjustable. This makes the Directory website look more attractive and responsive in the different devices.
Different maps like the homepage map, the category page map and the detail page map, all are responsive. They will maintain their alignment and render a seamless view in every device. To know how to set the height of the maps, refer this article.