Here's a passage that's been on my mind – probably a throwaway detail to most readers, but I liked it a lot and I'll tell you why in a bit:
Elide gazed across the flickering lights of the war camp, and a chill went down her spine. An army to crush whatever resistance Finnula had once whispered about during the long nights they were locked in that tower in Perranth. Perhaps the white-haired Wing Leader herself would lead that army, on the wyvern with shimmering wings.
I've always been intrigued by the way Sarah J. Maas uses different points of view. The Throne of Glass books are written in a third person omniscient perspective but each chapter generally follows one particular character at a time.
I love seeing things through Elide's eyes for the first time because it creates a richer picture of the world. For example, we've already come to know and understand both Abraxos and Manon Blackbeak in Heir of Fire, but Elide doesn't have that benefit. Her perspective grounds us back into the de facto culture of the Throne of Glass universe, a universe where Abraxos is a creature that is monstrous, dangerous, and untameable, period. And yet he has been tamed by this Blackbeak witch, who therefore must be even more monstrous and dangerous than the wyvern himself.
As readers, we go into a book series with certain assumptions... or sometimes it's certain things we've picked up along the way – it's like we have this basic understanding of a person, or a culture, or a history, that gets built up over time... which is why it's nice to remember that other characters live by other truths that don't always align with our own, simply because they haven't yet experienced what we have. Their perspectives help create a different and, might I add, refreshing picture of something we might already take for granted.
This is a long-winded way to say that I really liked this passage because of the way it described Abraxos as the wyvern with shimmering wings.