Stackshot Apple Tv 4
According to the Apple Developer documentation stack shot is to used collect all kind of information about a crashed process. 

Apparently you used a button combination that activates Stackshots. On iOS it’s works like this (assuming tvOS works almost the same);


  Stackshots
  
  For freezes or hangs with your iOS device, or when stackshots are requested, please follow the instructions below to capture and attach them.
  
  Press the Home button and either volume button on the device at the same time
  
  Note: Press the button combo several times to capture a series of stackshots


https://download.developer.apple.com/iOS/iOS_Logs/Stackshot_Logging_Instructions_iOS.pdf