core/homeassistant/components/icloud/icons.json

{
  "services": {
    "update": {
      "service": "mdi:update"
    },
    "play_sound": {
      "service": "mdi:speaker-wireless"
    },
    "display_message": {
      "service": "mdi:message-alert"
    },
    "lost_device": {
      "service": "mdi:devices"
    }
  }
}