Re: airplay from iphone6+ to apple tv
It depends on what you're watching and/or how you're watching it. For example, if you're "mirroring" a game that only plays in portrait mode, it will not fill the TV screen. Many games that play in landscape mode will fill the entire TV screen. In regard to videos, turning the device to landscape mode can help, but a majority of the videos I've watched via AirPlay on my ATV fills the entire TV screen whether in portrait mode on the phone or not.