Jess Rabble is a freelance photojournalist who in CE 72 was hired by Matias to observe and report various situations in the world. During one such assignment, he was to observe what was going on at Genesis Alpha where he met Lowe Guele. The Junk Tech took a liking to Jess and decided to help him by giving him the ZGMF-X12 Astray Out Frame, and loaning him the AI computer 8, who did not want to go with Lowe to Mars.
Jess is frequently described by others as a 'curious onlooker' and is even nicknamed 'Nosy Jess' due to his habit of getting involved in matters that interest him, even if they do not concern him. He is dedicated to finding and revealing the "truth" as seen by him to others. He reports the situations on the battlefield through the view of a mobile suit with the Out Frame's gun camera.
He seems to have a slight rivalry with PLANT news reporter Bernadette Leroux due to their differing views of how journalists should act. Though Bernadette initially has no respect for Jess because of his appearance and did not consider him a real journalist because of his willingness to get involved and interfering with the subjects he is reporting on. Jess initially dislikes her because of how casually she dismissed him and how she has a tendency to spin the truth into propaganda. However the two eventually come to understand the other's ideals and will respect each other for those at least.