According to the book, Favreau took notes during rehearsals, when improv was a little looser and more conversation was happening. Favreau took things Paltrow said and ported them directly into the film’s script. For example, there was a scene wherein Favreau was describing the scene’s background art to Paltrow, as her character would be knowledgeable in it. Paltrow, however, knew more about the art than Favreau did and corrected him several times. Favreau was so fond of her knowledge that he wrote a scene wherein Pepper provided similar corrections to Tony Stark.
In a notable scene, Pepper wears a slinky blue evening down to one of Tony Stark’s well-moneyed galas at the Walt Disney Concert Hall in Los Angeles. Pepper notes comedically that she’s not wearing deodorant. This was a comment Paltrow made herself regarding slinky gowns that reveal one’s armpits; deodorant would, of course, be visible in such a garment.
Favreau, Downey, and Paltrow were all struck by a wild rush of inspiration during the Concert Hall sequence and one of them decided, in the heat of the moment, that there should be a romantic interlude on the roof of the building. The crew had to rush to keep up as the actors and directors ran around to their hearts’ whims. Favreau said:
“This is one of those scenes where everyone from the studio is looking at you like you’re crazy because it’s four in the morning, and you’re doing ten takes, and you’re running in and telling them to do something completely different from the last time.”
Ultimately, the romantic improvisations were cut from “Iron Man,” as the filmmakers wanted to save the love story for a potential sequel.
Little did they know, in 2008, just how many sequels they’d get.