A user over on Reddit accidentally found something awesome while playing Wolfenstein: The New Order on the Playstation 4.
While attempting to use the Remote Play feature, user i_am_a_banana found that the Vita can also be used as a second screen, displaying the current level map and the HUD. There’s even an option to turn the HUD off on the main screen (the television, presumably).
There aren’t that many games that actually do this on the PS4 – it’s awesome when one comes along that does.
[Source]