As he tells his fabricated life story to Dora in the opening minutes of the movie, Don repeats this whopper—we mean, his personal motto—three times.
ROD FROM THE PUBLICITY DEPARTMENT: Lina, you're a beautiful woman. Audiences think you've got a voice to match. The studio's gotta keep their stars from looking ridiculous at any cost.
COSMO: No one's got that much money.
Cosmo gets in a great jab at Lina here, but don't overlook Rod's honesty. This is what PR people do—create images by only communicating certain kinds of info to the adoring public. At least he's upfront about it.
DON: What's the matter with that girl? Can't she take a gentle hint?
COSMO: Well haven't ya heard? She's irresistible. She told me so herself.
Here, we get another sick Cosmo burn, but there's a lot of truth to it. To the public, Lina has an awesome reputation. It's built on a big stack of lies, but it's still a positive reputation.
KATHY: Oh, you can laugh if you want to, but at least the stage is a dignified profession.
DON: (scoffing) Dignified profession.
KATHY: And what have you got to be so conceited about? You're nothing but a shadow on film... a shadow. You're not flesh and blood.
Kathy really shakes Don up with her character assassination of silent film stars. She makes him start questioning the roots of his reputation, which, like Lina's, is all movie magic.
DON: Tell me the truth. Am I a good actor?
COSMO: As long as I'm working for Monumental Pictures, you're the greatest of 'em all.
See? Kathy's got Don probing the very essence of his reputation.
DON: Now look, R.F., the owner of the Coconut Grove may do what Lina tells him to, but you're the head of this studio.
R.F.: Yes, I'm the head of this studio. She's hired! But don't let Lina know she's on the lot.
Do you think maybe, just maybe, the reason why Lina doesn't respect R.F. is because she knows he's afraid of her?
DON: I'm no actor. I never was. Just a bunch of dumb show. I know that now.
COSMO: Well, at least you're taking it lying down.
DON: No. No kidding, Cosmo. Did you ever see anything as idiotic as me on that screen tonight?
KATHY: Yeah, how about Lina?
Don not only tries to admit defeat here, but also that his superstar reputation was built on lies and that he isn't worthy of respect. Fortunately, he's got Cosmo and Kathy there to build his sorry butt back up.
LINA: You mean it's going to say up on the screen that I don't talk and sing for myself?
This is the realization that sets Lina on her path of (attempted) destruction. Why? Because it's going to destroy her reputation.
LINA: What do they think I am? Dumb or something? Why, I make more money than—than—than Calvin Coolidge! Put together!
For as funny as this line is, Lina's basically saying, "Don't they know who I am?!" As in, her reputation: A) precedes her; and B) suggests she's someone who shouldn't be messed with.
DON: Ladies and gentlemen, stop that girl, that girl running up the aisle. Stop her! That's the girl whose voice you heard and loved tonight. She's the real star of the picture. Kathy Selden!
Don shows his love for Kathy by saving her professional career and her reputation. Pretty progressive for 1927, don't you think?