XCode Screen capture as compared to Device Size in one informative graphic. Note that the right hand image, labeled as the device image, was edited with Gimp’s transform tool after being created with the iPhone 5’s camera.
As can be seen from the image, the Overlay, even when applied on the the smart TV, in this case a Vizio, still doesn’t work as expected on the device. The XCode screen capture tool will ignore any issues and capture the full screen include any non visible areas from the user’s perspective. Apple does suggest, however, to use the “UIScreen overscanCompensationInsets” property.