Here's the context of the quote:

“The thing about elves is they’ve got no . . . begins with m,” Granny snapped her fingers irritably.

“Manners?”

“Hah! Right, but no.”

“Muscle? Mucus? Mystery?”

“No. No. No. Means like . . . seein’ the other person’s point of view.”

Verence tried to see the world from a Granny Weatherwax perspective, and suspicion dawned.

“Empathy?”

“Right. None at all. Even a hunter, a good hunter, can feel for the quarry. That’s what makes ‘em a good hunter. Elves aren’t like that. They’re cruel for fun, and they can’t understand things like mercy. They can’t understand that anything apart from themselves might have feelings. They laugh a lot, especially if they’ve caught a lonely human or a dwarf or a troll. Trolls might be made out of rock, your majesty, but I’m telling you that a troll is your brother compared to elves. In the head, I mean.”

“But why don’t I know all this?”

“Glamour. Elves are beautiful. They’ve got,” she spat the word, “style. Beauty. Grace. That’s what matters. If cats looked like frogs we’d realize what nasty, cruel little bastards they are. Style. That’s what people remember. They remember the glamour. All the rest of it, all the truth of it, becomes . . . old wives’ tales.”