Throughout the video there are reflections, that looks a LOT like someone playing with a sheet of reflective Mylar and it would give it that effect, it's a very old 1970's trippy sci-fi effect that was used a lot in things like Space:1999.
There is also a reflection from 1:32 - 1:36 of someone reflecting the sun as if with a mirror, or Mylar again, this was prominent in the cosecha transmission as well.
Then at 2:47 you have again Mylar like reflection onto some kind of masonry and then again the mirror reflection in the cut just after that, definitely again
And at 1:51 on the left side wall you can read what looks like Fiction spray painted on the wall.
There are tons of little details in there, but reflection wise that covers it, it's definitely not the sun shining through or at leaves and things, the reflection shows what you would expect of a reflecting non-uniform surface. I've played with Mylar a lot, and this looks just like what it would create.