Things were different with her now. Exquisitely, massively, dangerously different. She had been recruited by a CIA case officer — with whom she had fallen in love — then vetted, trained, and directed to return to Moscow as a penetration of the Center.
-- Narrator (Chapter 1)

Importance: This quote indicates how much life has changed for Dominika since she began spying for the CIA and fell in love with Nate.

It normally could be considered a towering compliment when the president of the Federation specifically designated an officer in the Service to manage a high-profile recruitment operation — it had happened occasionally in the past with old KGB favorites of Putin’s — but Dominika was under no illusion about why she had been selected.
-- Narrator (Chapter 1)

Importance: Dominika knows it is because she is an attractive woman and a Sparrow that Putin had selected her to try to recruit Jamshidi.

The mullahs would execute him if his twisted little habits...
-- Jamshidi (Chapter 1)