iPhone Screen Shadow
That looks like a clear case of LCD image persistence which might go away in a few hours or day or might require service to exchange the panel if those changes are permanent. Depending on how long the image was static - you probably won't see the ghosting after it's off for a few hours or the panel gets used to the new pattern you are displaying on those pixels (retaining that image rather than the old one).

Software defects would show up in the screen capture and this is a very common limitation of plasma and LCD displays due to the physics behind how they produce and filter light.