Aircraft N379HA is one of many A330-200s with Hawaiian Airlines. On 17 July 2018, it arrived a little after 7am with one of its winglets removed.

My guess is that it was damaged while the plane was on the ground. Rather than continue to fly the jet with the damaged winglet, the airline decided to simply remove it.

I'm not sure how long this aircraft's been flying without the winglet, nor do I know the reasoning as to why it was removed.