Mon-El arrives to help Kara against the Parasite by leaping into the fight, as unlike Kryptonians, he cannot fly. This method of locomotion was used by Superman when the character was first created in 1938, as referenced in the line "able to leap tall buildings in a single bound" from the first animated Superman films. Mon-El's inability to fly, his comparatively weaker invulnerability and strength, and his lack of super senses are about the same as Superman's original power levels before they were gradually increased by successive writers.
When Mon-El is teleported to the DEO wearing only his underwear, a female DEO agent can be seen checking him out as she passes in the background. Later on, when he is arguing with Kara, she passes by again and he greets her by saying "Good to see you, Dana!"
During the final battle with Mxyzptlk in the in the Fortress of Solitude, Kara is seen drinking a glass of orange juice. This is a callback to the beginning of the episode; when he first appears, Mxy explains that, despite being all-powerful, drinking orange juice is one of the few things he can't make her do.
Mxyzptlk teleports Mon El to a theater stage, dresses him in colonial period garb, and refers to him as Hamilton before their duel, referencing the popular stage musical "Hamilton".
Mxyzptlk sings "A Whole New World" from Aladdin (1992). Gilbert Gottfried, who voiced Iago in that film, also provided the voice of Mxyzptlk in Superman: The Animated Series (1996).