In one of the last episodes of Star Wars: Rebels, Jedi Kanan Jarrus sets off to rescue the Rebel leader (and his lover) Hera Syndulla, who has been captured by Grand Admiral Thrawn. Concerned that this affection for her is clouding his judgment, he performs a ritualistic hair-cutting not unlike when padawans chop off their braids when becoming masters.
Many believe Kanan giving himself a Bushwick mullet is meant to signify his readiness to progress to the next part of his life, perhaps willing to sacrifice himself to save the woman he loves. Which, spoiler alert, he does, dying later that very episode while holding back a massive explosion from a ship carrying Hera, Ezra, and Sabine.
Sabine’s haircut ritual follows Kanan’s almost exactly—if you watch the video above, you can see that Kanan kneels down before a table, places the mask he wears on it (like Sabine does with her helm), grabs a knife, holds it out in front of him, and then chops his ponytail off. Sabine’s haircut signifies her willingness to rejoin Ahsoka as her padawan, and go back down the path of the Jedi.