Irony of the Gas Tank
When Margo's car runs out of gas, causing her to miss her performance, she remarks that Karen "didn't personally drain the gasoline out of the tank" The dramatic irony of this is that Karen did drain the tank as an act of sabotage, so Eve could go on in Margo's place.
Irony of Fame
At the beginning of the film, Eve accepts her award with the line "every night...different hundreds of people love you," implying that she feels happy and loved in her career. We then watch as she pursues this happiness relentlessly, only to learn the irony of the fact that Eve feels terribly lonely in fame, despite the love she gets from the audience.
Irony of Eve's Award
Since the film begins with Eve winning an award, the audience already knows that she is going to be famous. Therefore, watching the rest of the film contains a sense of dramatic irony, as the innocent-looking Eve fools everyone but the audience, who already knows she will achieve her goals of fame.
Irony of Cora
Karen is blackmailed into making Lloyd cast Eve, not Margo, as Cora in his new play. However, ironically, when she plans to do so, Margo suddenly decides she doesn't want to play Cora after all, making Karen's blackmail unnecessary.
Irony of Margo the Junkyard
Bill calls Margo his "wonderful junkyard," an endearing term that satirizes her age. This exchange, in which Bill seems to insult his paramour, rather ironically shows that Margo is much happier in this relationship than Eve will ever be, because Margo has someone in her life who doesn't care about her age or appearance.
