[Spoilers] During my first TFA viewing I thought that the Snoke hologram was going to turn out to be a Great And Powerful Hux projection: an ancient-looking disguise with an air of authority that would allow the youthful-appearing Hux to give orders to the First Order and KR. (“Pay no attention to the Hux behind the curtain”). However, I was surprised to see a later scene that showed Hux speaking one-on-one alone to the Snoke hologram, so that theory would only work if Hux were a sort of Dr.-Hux-And-Mr.-Snoke split personality. That would be quite a stretch.