In order to add a section, you need to go to Customizer → Add Section → Column image.
Section settings
Images row
Heading - the title of the section;
Image aspect ratio - aspect ratio of the images. Can be Square, Landscape or Portrait;
Layout
Container width - a container width of the section. If the “Inherit” value is selected then the container width is based on the group 'Layout' settings in the Theme settings;
Desktop offset top - the top indent of the section on the desktop;
Desktop offset bottom - the bottom indent of the section on the desktop;
Mobile offset top - the top indent of the section on the mobile;
Mobile offset bottom - the bottom indent of the section on the mobile.