What does the Lord of the Flies look like when Ralph sees it in Chapter 12?

When Ralph finds Simon's hiding place in Chapter 12, the pig's head is now a pig's skull, the flesh having been eaten away by the swarming flies. At first he sees "the thing as lifeless" but then when he looks levelly at it, it seems to grin and "hold his gaze masterfully and without effort." The skull then seems to "[regard] Ralph like one who knows all the answers and won't tell." Ralph senses that the skull is significant, but, unlike Simon, does not understand any further.