I figure she's channeling some kind of deep intuition/ESP as she figures out what is going on at the scene. Researcher Joan Cohen writes:
I think that it is supposed to show her conflict -- she knows she should be with her guy but she loves the job -- she is a deep thinker -- like a Scandinavian cop -- they don't talk a lot! Also, her partner is played as kind of dumb and instinctual, so she is supposed to be the smart one -- he is street -- she is deep!
UCLA's David Chute cites Georges Simenon's Inspector Maigret:
”…at that moment Maigret was living in a world of his own and not in the present at all, and he answered [Louis] half–heartedly without really knowing what the question was.
Many a time at the Police Judiciare, his colleagues had joked about his going off into one of these reveries, and he also knew that people used to talk about this habit of his behind his back.
At such moments, Maigret seemed to puff himself up out of all proportion and become slow-witted and stodgy, like someone blind and dumb who is unaware of what is going on around him. Indeed, if anyone not forewarned was to walk past or talk to Maigret when he was in one of these moods, he would more than likely take him for a fat idiot or a fat sleepyhead. “So, you’re concentrating your thoughts?” said someone who prided himself on his psychological perception. And Maigret had replied with comic sincerity: “I never think.”
And it was almost true. For Maigret was not thinking now, as he stood in the damp, cold street. He was not following through an idea. One might say he was rather like a sponge. It was Sergeant Lucas who had described him thus, and he had worked constantly with Maigret and knew him better than anyone. “There comes a time in the course of an investigation,” Lucas had said, “when the patron suddenly swells up like a sponge. You’d think he was filling up.”
But filling up with what? At present, for instance, he was absorbing the fog and the darkness. The village round him was not just any old village. And he was not merely someone who had been cast into these surroundings by chance.
He was rather like God the Father. He knew this village like the back of his hand. It was as if he had always lived here, or better still, as if he had created the little town. He knew what went on inside all these small, low houses nestling in the darkness. He could see men and women turning in the moist warmth of their beds and he followed the thread of their dreams. A dim light in a window enabled him to see a mother, half-asleep, giving a bottle of warm milk to her infant. He felt the shooting pain of the sick woman in the corner and imagined the drowsy grocer’s wife waking up with a start.
He was in the café. Men holding grubby cards and totting up red and yellow counters were seated at the brown, polished tables.
He was in Genevieve’s bedroom…”