the roof of the pool greenhouse is plastic which is translucent but not transparent - to reduce the harshness of the sun, an also to save weight.
the walls are clear glass for the views.
it looks similar to image below, but larger and with a separate hot tub:
when i first saw it i was skeptical it would work in our cold climate here in US North-East but it works perfectly. i under-estimated the greenhouse effect. it seems to easily overcome the relative lack of insulation.