Where is this variable defined?

[Kent Multer]

In the notification-banner content section, there's this:

        <picture>
            <source srcset="https://www.labrada.com/store/&mvt:global:ros_desktop:image;" media="(min-width: 1040px)" />
            <source srcset="https://www.labrada.com/store/&mvt:global:ros_tablet:image;" media="(min-width: 768px)" />
            <img src="https://www.labrada.com/store/&mvt:global:ros_mobile:image;" class="&mvt:global:ros_desktop:css_class;" alt="&mvt:global:ros_desktop:image_alt;" />
        </picture>

Where are g.ros_desktop:image and the other varaibles defined? How do I change one?

Thanks --

[Kent Multer]

Follow-up: Never mind, I figured it out after I noticed that the content section also contains these lines:

    <mvt:item name="readytheme" param="Load_image( 'global_banner_desk', g.ros_desktop )" />
    <mvt:item name="readytheme" param="Load_image( 'global_banner_tablet', g.ros_tablet )" />
    <mvt:item name="readytheme" param="Load_image( 'global_banner_mobile', g.ros_mobile )" />

These are images that are assigned on the ReadyTheme Images tab.