I imagine you could dummy-up a person with a jetpack by starting with balloons stuffed into a tyvek suit.
This was on 21/21, and surface winds at LAX were from the East until noon - though a balloon/drone combination would not be at the mercy of light winds.
Yeah, that's what it looks like to me. The posture looks pretty unnatural and the "pack" is ridiculously small given the altitude it's been spotted at.