Actor Allusion - Like her voice actress Elisa Gabriellia, Sonia has a beauty spot on her left cheek.
Apologises a Lot: Rocky (voiced by Kelly Ripa) is a klutzy scientist working for Wayne Enterprises that apologizes frequently, even if there is no reason. Though this is arguably a covers, making this a subversion of sorts.
Art Shift - This film was made after the "revamp," which was an artistic redesign between the original animated series and The New Batman Adventures, and was drawn in the style of the latter. Rupert Thorne had never appeared after the original revamp, so a new design had to be created to match his character with the art-style of the rest of the film. Though more "streamlined," it is nigh-identical to his previous design.
Batwoman - A re-imagining of the character, originally created in 1956. Her original identity is alluded to with Kathy Duquesne, whose name is phonetically similar to the original Kathy Kane.
Bittersweet Ending: Predominantly more sweet than bitter, but it is not without its sadness. Rocky gets her fiance out of jail and Kathy gets her family out of the mob business, but Sonia is forced off the police force.
Call Forward: The photo of Bruce and Barbara on a boat that appears in Batman Beyond episode "Out of the Past" appears in this film.
Dating Catwoman - Bruce goes out with Kathy, daughter of notorious crime boss Carlton Duquesne, a few times. Given that he is the Trope Namer, this is not surprising.
Deadpan Snarker - Alfred, as per usual, and Tim Drake gets in a few good ones as well.
Roxanne: Yeah. Fortunately my boyfriend is very understanding. What about yours? *pause* Girlfriend, I mean! Of course, girlfriend! I mean, considering your reputation and- NOT that it's bad or anything or even any of my business, because it's not, I was just curious! *stops suddenly* How red is my face?
Kathy Duquesne's name is a reference to Kathy Kane, the comics Batwoman's secret identity. Executive Meddling prevented her from actually being Kathy Kane, since this version of Batwoman is too antiheroic.
Interquel - Between Batman The Animated Series and Batman Beyond. Many features of the Beyond batsuit are taken from Batwoman's and it sets up the Bruce/Barbara relationship mentioned in the latter series. Tim Drake is still Robin and visibly older than his appearance in The New Batman Adventures, but it is before the flashback scenes in Batman Beyond: Return of the Joker. The film also features newly developed laser rifles that are likely the same as the ones that become ubiquitous in the Beyond era.
Let's You and Him Fight - Played with. Batman is out to stop the reckless Batwoman, but in their first face-to-face encounter he comes to her aid when she is surrounded by Mooks. They later have a scuffle, but there is no real misunderstanding at work - she just does not want Batman to stop her.
Lighter and Softer - As compared to other Batman animated films. In the clearest departure from its roots, more scenes take place in the daytime.
Omnidisciplinary Scientist: Batwoman is a brilliant martial artist who also invented miraculous gadgets and is a skilled and experienced computer hacker. It turns out it is three different women using one costume who each bring their own skills to the table.
The Other Darrin: David Ogden Stiers replaced Paul Williams as the Penguin and Hector Elizondo replaced Henry Silva as Bane.
Role Reprisal: John Vernon reprised his role of Rupert Thorne in the movie.
Screw This, I'm Outta Here: After spotting Batman rummaging around in a room (who gives him a rather displeased look) a mook quietly leaves the room and tells his buddy he saw nothing.
She-Fu: Penguin's waitresses-slash-cronies. It's a better showing than the actual series, where they only used cautiously-held handguns and were quickly neutralized.
Barbara: But... spring break will be coming up soon and I'll be back in Gotham for two whole weeks. (*suggestively*) Won't that be nice. Bruce: ... Yes. We'll all be happy to see you. Tim: Don't drag me into this.
Shout Out - The original Batwoman, Kathy Kane, is referenced by the identity of one of the women potentially behind the mask: Kathy Duquesne.
Took a Level in Badass: The Penguin's Bodyguard Babes. Their only real fighting appearance in The New Batman Adventures involved very lame use of pistols, but here they're full-fledged She-Fu-wielding badasses who give Batwoman a run for her money.
The Ugly Guy's Hot Daughter: We have the gorgeous Kathy Duquesne. She clearly didn't get her looks from her father Carlton.
You All Share My Story - Rocky, Sonia, and Kathy all have a beef either with a Bat-villain, or Carlton Duquesne. More indirectly, each shares a trait with Batman: Rocky his intelligence, Kathy his wealth, and Sonia his determination.