It looks like they had been taken by a rip current and the lady had exhausted her energy. In such a case one is very close to drowning. Most likely the guys man

It looks like they had been taken by a rip current and the lady had exhausted her energy. In such a case one is very close to drowning. Most likely the guys managed to bring her back close to shore before the drone had arrived, at which point she received the lifejacket. Women are normally much shorter than men, so that could be a reason. The beach in the video tends to have uneven grounds with deeper areas (rip currents tend to take place at the deepest point, that is if you swim sideways you might step on higher grounds). Still, a very decent solution if a drone can deliver a lifejacket before the jet skis/swimmers arrive.