By saying "Alexa," then announce, broadcast or tell everyone, followed by your message, you can gather the family or your roommates together for movie night without having to yell at everyone to make their way to the lounge. Alternatively, you can tell your family members who are busy watching TV to move to the dining room for dinner. The update is rolling out on Fire TV Cube devices in the US.
Another update arriving later this month will let smart doorbells or cameras send notifications to your Fire TV Cube. So, if Alexa tells you someone is at your door, you can say something like "Alexa, show me the front door" and the Fire TV Cube will display what your camera or doorbell is seeing on your TV. You'll be able to determine which notifications your Fire TV Cube receives and which devices broadcast your messages through the Alexa app's Alexa Announcements menu.