Adding an external icon is not supported yet. However, the Inovelli logo appears on the Devices catalog of the SmartThings app if you register the handler in that brand.
Generally, the icons used in the device card are the preloaded ones, depending on your device type and some are configured to show an active/inactive state based on the dashboard alternatives.
eg. for a switch (smart bulb), the properties needed in your DTH definition are:
Using this device type and the switch capability (or any other that has active/inactive alternatives configured) in the dashboard view, you’ll see the icon animation.