Development Gag: Jetta being half-black and half-Japanese is a nod to the character's original concept, as she was going to be black in the cartoon before Executive Meddling resulted in her being British instead. This is a rare case of a Race Lift actually being true to the creator's original intention.
Exiled from Continuity: Although the IDW staff place it as part of the newly-created Hasbro Comic Universe, it wasn't a part of Revolution crossover due to tonal issues, although references have popped up in the other comics (Ian Noble has a Misfits poster in his room). With the HCU's ending after the UnicronCrisis Crossover and subsequent reboot of the Transformers titles, the Jem title's presence in the new HCU (if there indeed is one) is unclear.
Promoted Fanboy: In 2011 Campbell posted several Jem redesigns on her DeviantArt and said she would want to work on a reboot. Come 2015 and she's the main artist of the comic reboot.
Unintentional Period Piece: The series is brimming with early-to-mid 2010s references. Likely intentional, since the original has several '80s pop culture, this comic should do just the same for the 2010s.
A few years before release Sophie Campbell posted some fan redesigns for the characters online. There are noticeable differences between the early designs and final ones.
Also, Synergy played a major role in Hasbro's failed Unit: E crossover comic from 2011; there, she was an alien AI who assisted characters from Micronauts in gathering info on many Hasbro-owned characters throughout the multiverse. Jem herself was mentioned as going to compose the "music of the spheres", presumably with Synergy's assistance.
Graphix, a character meant to be in the show before it was canceled, was meant to be in the comic before it was canceled. Also canned were original characters Shade and Misty.
A new character, The Fox, was supposed to replace Raya as drummer for the Stingers, but the comic was cancelled before this could happened.
Sophie Campbell had planned a one-shot story featuring axed 80s characters the Mongrels, but nixed this because 80s head writer Christy Marx was uncomfortable with the idea.
Awesome, Dear Boy: The whole reason why Kesha appears as Pizzazz. Jem is Kesha's favorite cartoon and when she heard they were making it into a movie she told her manager, "Get me in there."
Even on a tiny $5 million production budget, this still managed to flop. Its $1.38 million opening weekend was the worst opening ever for a film playing in at least 2,400 theaters.
And then it got worse: the week 2 gross was a paltry $387,925. After that, Universal pulled the film from wide release and actually stopped reporting the box office figures. The fact that it was pulled in so short a time is unprecedented.
It even managed to take the TV show down with it; Discovery Family unceremoniously dropped the reruns of the cartoon one week after Universal withdrew the film.
Casting Gag: Britta Phillips as a stage manager. Phillips provided the singing voice for the cartoon.
Reality Subtext: Possibly unintentional, and a truly sad example at that. As The Nostalgia Critic pointed out in his review, Aunt Bailey's financial woes are eerily similar to Ringwald's fall from grace since her days as a member of the Brat Pack.
Stillborn Franchise: A sequel was clearly envisioned judging by the post-credits scene. Presumably, it would have followed Erica using the Misfits as Jem's competition. As Jetta is already part of the Misfits here, Raya likely would have been introduced in the next film, too.
The Sony hack revealed that Hasbro was interested in Sony Pictures co-financing this movie (which was known under the code name "Pink Pony") as well as the film adaptation for My Little Pony: Friendship Is Magic. Sony was more interested in the latter over the former, due to its larger fan base, so they dropped Jem. Unfortunately for Sony, the negotiations for My Little Pony: The Movie never held up, and the film was eventually released through Lionsgate on October 6, 2017.
Originally the movie was going to be much more faithful to the cartoon, but no company would buy it.