I suspect Jon M Chu was chosen because he had taken a Hasbro production to success with GI Joe Retaliation and made two very sucessful Bieber documentaries. Much like Jem, which was once an 80's cartoon that followed He-Man, Chu's work appealed to men and teen and tween girls. Jimmy Fallon has a cameo in the film explaining that though Jem is for girls, he likes it too.
I have seen none of Chu's work, but I would say he certainly is quite good at filming musical sequences and has heartfelt and kinetic energy in this work, all of which serves Jem and the Holograms very well.
Aubrey Peeples stars as Jerrica. She has sisters and cousins and an aunt and a dead father (no mention of a mother). The whole family is musically inclined. Jerrica is the more introspective of the family and probably the most intelligent. She quietly records a song that gets uploaded on Youtube and becomes a viral hit, a great song in fact that could become a viral hit in the real world, under the name Jem. The film is litered with real Youtube videos of people trying to showcase various talents. It is a very nice touch.
The film is about hiding under names in an online, viral world, the deceptive world or marking and trying to maintain personal intergrity. A young rock girl is trying to help her aunt by signing a solo rock contract that will create tension with the rest of her family.
There are questions left on the table. Just how old is Jem's keeper and could he really run the business without it being held up in court for years? Why didn't Jem reveal her identity sooner insuring that her aunt would get some money through a TV exclusive on the story?
In the end though, it is kind of touching what Jem chooses to do with her identity. The film is sincere, has fine music and positive characters. It also has more of an 80s vibe to it then other attempts at recapturing the decade. That might sound odd because of all the Youtube references but it's there The very end, a montage of fan videos, is an obvious love letter to fans of the series. And any true fans of the cartoon should like this film.