Description, literary edge of genre

I'm reading a PD James mystery, and am contemplating the differences you find on the literary edge of a genre. For example, the "mystery" part of this mystery has developed very slowly (the murder happens well into the book), and much of the setup is detailed backstory and introspection of several characters as they enter the story action. (Thus the sleuth is introduced very late, only when he's called to the murder scene.) But I was also struck by the depth of description, even from those characters who don't seem that observant. Here's an example. Note the topic sentences at the start. This is an interesting technique: She states the conclusion first, and then describes what brought her to this conclusion. That is, she shows the POV character's judgment of what this means, and then what can be seen or heard to prove that to be true:

Without turning her head, she couldn't resist a glance at Dalgliesh. No one was better than her chief in concealing anger, but it was there for her to read in the momentary flush across the forehead, the coldness of his eyes, the face momentarily hardening into a mask, the almost imperceptible tightening of the muscles.

She told herself that Emma had never seen that look. There were still areas of his life which she, Kate, shared, which were closed to the woman he loved, and always would be. Emma knew the poet and the lover, but not the detective, not the police officer. His job and hers were prohibited territory to anyone who had not taken the oath, been invested with their dangerous authority. It was she who was the comrade-in-arms, not the woman who had his heart. You couldn't understand the job of policing if you hadn't done it.
She had taught herself not to feel jealousy, to try and rejoice in his triumph. But she couldn't help relishing from time to time this small, ungenerous consolation.

First, watch the (I think) less than adroit handling of the name/pronoun issue (two women-- "... she, Kate," then a "she" following "Emma" when "she" is really Kate), and yeah, I'm absurdly obsessed with this.

Also notice that descent into the personal at the end-- very nice. Kate starts out making a general assessment of her boss's behavior-- she can tell he's angry-- then describes what about his mien leads her to know that. Then there's that descent into her own psyche. She uses this awareness of his mood to tell herself that she knows him better than his fiancee does, to comfort herself that she is his colleague, if not his lover, and that might actually be better in some way. That she is almost consciously fooling herself is shown by that little "thought tag" (and this is why I think the "she thought" and "she mused" alternatives can be useful even or especially in deep POV) -- she told herself. If this had been "she reflected," we might have just thought she was stating the truth, but "she told herself" indicates subtly that she doesn't quite believe it herself, that she's trying to convince herself that she is in fact important to him.

I like that funnel technique, and think it can be used not just in these POV passages, but in scene design, from a general, somewhat impersonal approach, narrowing into the personal, the deep, perhaps the emotional. We might try that when we're working on a suspenseful scene, starting wide but aiming at a particular emotion (dread, fear) at the very end of the scene. We might even try a narrowing of POV from an almost-omniscient opening of the scene to a deeper POV for the action and then end the scene deep into the character's POV, feeling the emotion that results from whatever happens in the scene. The contrast between the opening distance and the ending closeness might intensify the intimacy.

Alicia