When an editor is selecting a component in CloudCannon, the icon from the component spec is used as the default thumbnail:
hero.bookshop.yml
copied
You can provide a custom image to use instead by placing a matching <component>.preview.<format>
file in your component directory. This will only be shown when adding new components to a page:
You can also specify a <component>.icon.<format>
file, which will be shown alongside existing components
in CloudCannon's array view: