As of now, it’s unclear how big the list of followers that you can stream to can be, but since Instagram didn’t mention anything about that, your Close Friends list can probably be very big.
Up until now, all your followers were able to watch a broadcast started from Instagram Live or Live Room, but with the new feature, only those included on the Close Friends list will be able to watch if you choose to stream only to your friends.
Instagram announced that this feature will be rolled out in waves to all users globally, so it might take a while until everyone gets access to it. You’ll be able to take advantage of the new feature once you see the “Close Friends” option, in addition to “Everyone” and “Practice,” when you want to start your broadcast.
This is a nifty little feature, which will encourage more Instagram users to take advantage of the livestream feature, without being afraid that some of their followers might not be interested in what they have to show and/or talk about.