Google is currently testing new features in Google Duo, such giving users the ability to call their Google Home devices and set call reminders.
The app now shows an option that says "Set a reminder to call later" when you click on someone's name, as outlined by XDA Developers. Once you click the option, it prompts you to enter a time for the reminder.
Although you can currently call your Google Home devices through Google Assistant, the new feature lets you do so directly in Duo.
The features aren't currently available to everyone, but will be useful once they start to roll out. However, since Google is just testing them, there's also a possibility that they may be scraped.
Source: XDA Developers