This episode marks the first appearance of Chalk Dad in the series proper; he previously debuted in the Oh Yeah! Cartoons short "Chalk Dad".
The music playing when Millie shows Rudy the tag she made for Joe's present was previously used in The Fairly OddParents short "The Zappys!", which aired as part of Oh Yeah! Cartoons along with ChalkZone. This is the second time a background music cue from The Fairly OddParents was used in ChalkZone.
This is the first time Penny's room is shown in the series. Her bedroom walls are pink in this episode instead of purple as they are for the rest of the series.
This is the first episode where Penny is shown (partially) without her glasses. It's shown that underneath her glasses, she has brown eyes. When she wears her glasses, they're black.
Millie's outfit is pink instead of blue and green in this episode only. Because this episode was one of the first episodes in production, this could be an early version.
This episode and "French Fry Falls" is the fourth episode of the series, but Nickelodeon aired it as the second. This may have been due to the episode being in production earlier.
The magazine that Joe is reading is a reference to the Popular Mechanics magazine.
The walls in Rudy's bedroom are green in this episode instead of yellow as they appeared in the Oh Yeah! Cartoons short "Secret Passages". They would appear green again in "The Wiggies" until they went back to yellow in season two.