Fabric panels in Pocketship cabin?

I had some time today while waiting for the epoxy to dry and did some nosing around in CLC’s website. I found Mr. Harris’s blog on a midwinter pocketship cruise and really enjoyed the read. It did make me pause when I saw the photo of the cabin had fabric panels on each side. I’m assuming this would be for condensation? Anyway - does anyone have additional information of this?