You can't credit or blame the screenwriter for set design, drawings, sketches, miniature sets, 3D models, and buildings. Rand was disappointed with architectural designs created by Warner Bros.' in-house set designers.
Actors choose cadence, sometimes guided by the director.
When she tells him that she might regard this as insubordination, he offers to bring over the supervisor to fire him. She intentionally cracks the marble base of her fireplace to have a pretense to bring him to her room for the repair work. He lets her know that he realizes she had this ulterior motive. Both then enact in a veneer of innocuous conversation, with both slyly aware of their double-entendres. Dominique's aroused eyebrows tell us that she knows that he's no longer talking about limestone but about testosterone.