That drone plays into gameplay in the single-player campaign, and it's also a unique aspect of her rank among Galactic Federation soldiers.
"It's kind of what separates Iden from the rank and file Stormtrooper, it's what makes her part of Special Forces because you know, the Empire is known for its technological prowess and so giving her this combat ready droid gives her a greater range, a greater reach, more versatility, more flexibility," game director Mark Thompson told Eurogamer in a recent interview.
From the sound of that, we're guessing that the drone enables various "powers" in the game — both combat- and movement-based powers.