- Acting for Two: The actors playing the Nisses also play Gertrud, Oluf, and Benny. Benny and Fritz are the only characters played by the same actor to actually meet.
- In addition, in the Finnish version, the narrator and Gammel Nok are played by the same actor.
- Played for laughs when Hansi gets a crush on Gertrud, both of whom are played by the same actor.
- Actor Allusion: Gammel Nok points out he was a famous actor in the final episode. He was played by Poul Bundgaard in the Danish version, who was a member of Olsen-banden, ("the Olsen Gang") from the famous movie series of the same name. Same for Arve Opsahl in the Norwegian versions of The Julekalender and the Olsen Gang. In the Finnish version, Gammel Nok was played by Jukka Virtanen, a famous actor (among other things) in his country.
- California Doubling: In the Finnish version, the story almost exclusively takes place in Keuruu, Finland. However, interior scenes were shot in Aarhus, Denmark and the exterior scenes in Ruka, Kuusamo, Finland.
- The Danza: Possibly in the Danish version where Oluf and Gertrud's dog is named Emil — just like the animal that was cast in the role.
- Prop Recycling: Many of the props from the Danish version were re-used in the Norwegian remake, and a huge part of the props in the Finnish version are from both the Danish and the Norwegian versions. Even some sound clips were recycled.
- Technology Marches On
- Oluf and Gertrud use a landline telephone, their television looks really old and they listen to cassettes.
- Benny uses a wooden abacus. Played for Laughs at least in the Finnish version where he humorously calls it his "computer".
- What Could Have Been:
- De Nattergale had an idea that the Nisses could speak an entirely new language. However, the authors found it too difficult, so they decided to use a mix of Danish and English instead.
- Trio Saletti, the creators of the Finnish version, intended to make a sequel, but they had to abandon the idea due to copyright and licensing issues.
- Travellin' Strawberries, who starred in the Norwegian version, also wanted to make a sequel. Tor Gunnar Heggem, who had worked alongside the trio on translating and adapting the original Danish script to Norwegian, even wrote a script for the sequel — it featured all the characters from the original, and the premise was that Olaf and Gertrud were going on vacation to Rhodes, like Gertud's sister did in the original, but got on the wrong plane and ended up on Svalbard instead. However, the Danish producers didn't want to give permission for a sequel, and so it was never made.
Trivia / The Julekalender