It feels like a different approach for them this time around. Usually they come up with some sort of theme ('noise' & 'beauty' for Rhapsody, 'life' for GIFT, the darker tone of zeitgeist, etc) and try to evolve their sound by exploring that theme, but here it feels like more of a celebration of everything that's already come before; everything all rolled up into a single concise package. I suppose a rather cheesy way of putting it is that rather than always looking forward to the next destination, they've taken a moment to rest and look back on the journey so far. In a way it's sort of like a best-of album with all new songs.