Solar Balloons Not Quite Satelloons

So I’m staring at these Solar Balloons by Coolearth Technology, caught like a deer in some headlights [actually, with this pair, maybe it’s “caught like a spring breaker in some headlights, but whatever], and I can’t figure them out.
Then I get it: one half of the balloon is clear; the parabolic–or parabola-like, anyway–reflector part is the inside surface of the other, opaque side of the balloon. 2-meter diameter. Not Satelloon-scale, but still, it’s good to know it’s out there.
Solar Balloons from Coolearth Technology [coolearthsolar via inhabitat]