She looks and acts like a discounted rip-off of Wyldstyle from The Lego Movie and Olivia "Sombra" Colomar from Overwatch, both in personality and character design because all three characters have blue hair (or purple for Sombra) and are notorious hackers, but with none of the charm and likability those two characters had.
She gets no character development for most of the movie and has very flat characterization throughout the movie other than revealing that she was formerly a princess. (Well, in hindsight every character in The Emoji Movie has this same problem.)
Her relationship with Gene feels forced, bland and dull.
She seems to have a bad temper towards others around her to the point of being unlikable, but this is partially understandable considering how she was treated by her mother as a kid.
Basically, she is almost a Mary Sue with no personality other than being a strong, independent female character, who mostly exists as woke pandering to promote girl-power.
Speaking of girl-power, she spends two moments complaining about how sexist she perceives the society she lives in to be, but then changes back to her former self in the end of the movie, (the princess emoji) which as mentioned above she assumed as sexist, hereby making her look like a complete hypocrite. Other than that, she usually talks about what other things not related to feminism, including the princess and bride thing being a myth, and her motivations.
Not only that, her claim of female emojis being only princesses and brides falls flat on its face when considering Mary Meh (Gene's mother) and Smiler are both females that aren't princesses or brides. In fact, the latter was even the original emoji and founder! There no reason Jailbreak shouldn't be able to go as a hacker.
She is also an example of a satellite love interest, which is to say a love interest of the main character who is underdeveloped.
Her voice acting by Anna Faris is shockingly mediocre.
She, along with her friends, didn't show any mercy for Akiko Glitter (from Just Dance) and other likable characters that were deleted from existence and were responsible for all the destruction.
In the Emoji Movie junior novelization, her temper is even worse. This can be blamed on Hi-5, who was made into an even more insufferable character in that book.
Her design is somewhat decent, like every Emoji Movie character, despite it being unoriginal.
She does have her weaknesses, such as the inability to enter the cloud alone and dance, which at least doesn't make her a complete Mary Sue.
At least she apologized to Gene for what happened in the Cloud.
She does help others around her at least.
In the short film found on the DVD, Blu Ray, and some of the HD digital copies, titled Jailbreak Decoded, some of her bad characterization is justified as her strict single mother had treated her unfairly as a child. Some of her characterization is also explained in the book adaptation, The Emoji Movie: Break Out.
Jailbreak was originally set to be voiced by Ilana Glazer in the film, but for unknown reasons, she was replaced by Anna Farris for the role.