Denise Richards, who played Russell Dalrymple's (Bob Balaban) 15-year-old daughter, was actually 21 at the time the episode aired.
While writing the pilot script Jerry and George cut the Elaine character out because they don't know how to write for a woman. This mirrors the fact that Julia Louis-Dreyfus wasn't in the pilot of Seinfeld.
This episode saw Seinfeld move from its regular Wednesday time slot to Thursday, airing after Cheers (1982), which was in its final season. The main four characters appeared in a segment that aired during the Super Bowl, advising viewers of the change. There were fears that new viewers of the show would be unaware & confused by the story of Jerry (Jerry Seinfeld) and George's (Jason Alexander) NBC pilot, but the popularity of the show turned out to be higher than ever.
Jerry and George saying they can't write lines for a woman character mirrors Seinfeld and Larry David's own concerns when they wrote the original pilot Good News, Bad News (1989). Julia Louis-Dreyfus didn't appear as Elaine until the second episode The Stakeout, after a directive from the network that they needed a female character, prompting a crisis among the writing duo.
When Elaine reprimands Jerry and George for looking at a 15-year-old girl's cleavage, Jerry says he doesn't pay attention to age while looking at cleavage. During this time in real life, Jerry Seinfeld started dating an 18-year-old Shoshanna Gruss (Lonstein). They were together for 4 years.