This is the first episode, and one of few, where the Cures don't use their finishing attack.
When explaining several elements of broadcasting, she refers to Clarice Ichida as "talent". Some of the boys snicker at that. Clearly they're as much fanboys of a certain mother of modern magical girl anime as the author is.
It's hinted that each of the four Flat Circus enforcers don't seem to know that the other three are Flat Circus enforcers, too.
The Deuce of Spades is introduced in this episode; he's of enormous girth, but otherwise fits the Dick Dastardly/Snidely Whiplash villain stereotype.
Ken asks Megumi in one scene if a prima ballerina stuck a silver spoon in her mouth. This is a reference both to the idiom "born with a silver spoon in your mouth" and her English dub voice actress Emma Watson's godmother being the Bolshoi's own Svetlana Zakharova.
Megumi returns the favor with another double-reference one-liner. Her referring to Ken as "the very model of a modern English schoolboy" references both Emma Watson's "sexy English schoolboy" line in The Perks of Being a Wallflower and the Gilbert and Sullivan tune "I Am the Very Model of a Modern Major General".
Following that, when prompted, Megumi proceeds to start singing "The Elements" before Ken interrupts her.
As they start fighting the ninja, Megumi and Ken recite their own spin on the infamous "Helter Skelter" nursery rhyme ("One, two, three, four, five, six, seven. All good children go to heaven.").
This is the first episode to feature any variation on the costumes worn by the Cures; the concept of costume variations is explained briefly after Cure Red finds out she and Cure Cyan are wearing variations on their respective Cure costumes.