He's a door gunner.
1. He is easily tied as a pilot class Clone with that helmet.
2. Not having much upper body armor is consistent with someone who camps out behind a big gun, not often close to small arms fire to the point bulky chest armor would matter for him. If anything kills him, it's taking the whole gunship down.
3. Having leg armor makes sense, as the time when he is close to small arms fire (troop drops), that fire would come from lower angles.
4. Less armor on the arms means he can hold them up for longer periods of time with less fatigue. This is important if he's running a heavy gun for long periods of time.
5. The pilots gloves make more sense as they would be be suitable for the battlefield and would give him better feel for his weapon controls.
6. The small plate of armor the rebreather is fitted to would allow him to more comfortably bring his hands together in front of him (take a large dinner platter, lay it on your chest and then bring your hands together out in front of you like you're aiming a pistol. Do that with a smaller dinner plate. The latter is much more comfortable and you can maintain the posture for longer periods).
I made a super-quick PShop of how I'd paint him up, attaching him to the Star Corps.