At the Reno ranch, Countess DeLave exclaims "I've always put my faith in love. Still... I have had four divorces." However, earlier on the train, she had explained that her first husband left her a widow (and left her all his money) and she had only divorced the following three.
When Mary is reading in bed, the early long shots show the lamp on the left side of the bed to be a male figurine, and the one on the right to be a female. In the close-ups, the lamp on the left of the bed has changed and is female.
When Mary is on the phone with Stephen during the lunch party, she puts a cigarette in her mouth and strikes a match, lighting it, the cigarette doesn't light, and she holds the unlit thing through the rest of the conversation. When they cut to long shot of her hanging up the phone, the cigarette is smoking, and she stabs it out in an ashtray.
When Crystal is taking her bath she smokes a cigarette, which she eventually throws away. However when Little Mary enters the bathroom, Crystal is again smoking and we never see her lighting this other cigarette.
When Countess deLave reveals Buck's true financial position, Crystal has one hand resting on the door frame, then drops it to her side as Miriam and Sylvia come over to rub in the bad news. Then in the close-up when Crystal says, "There is a name for you ladies..." she takes her hand off the door frame again.
When Cristal is talking to Buck on the phone she says that she has been married for 18 months and yet the next day Mary is giving an annual 2 year party for the girls. She and Steven were married on the day that he and Mary were divorced and her party is to commemorate that event.
Barn doors for a sound stage light appear to be hanging from the 'ceiling' in Mrs. Haines' living room. It is visible during Mary's conversation with her guests from the moment where Peggy helps her put on a necklace, up until they leave the room.
As Lucy hauls Sylvia into the house after her fight with Miriam, the camera (after panning from left to right, following them) quickly jerks back before the film cuts away, indicating that had the camera panned over any further, the set would have been revealed.
While Miriam Aarons is in the process of convincing the Countess De Lave to romantically pursue cowboy Buck Winston (specifically urging the Countess to put him into radio), the Countess appears to refer to him as "Buck Newport." However, she actually says, "I fear I'd never make a success of Buck at Newport," referring to the Newport Music Club, which would later give rise to the Newport Music, Jazz, and Folk Festivals.