These were similarly factory installed on some Land Rovers through the fifties, sixties, and seventies. Mostly used in sweltering hot jungle-environments and across the African savannah. Sometimes this was referred to as African Air-conditioning.
It was a second roof fastened over the original roof with spacers and it had porthole-openable vents.
The idea was to let the inside heat rise up and out of the vehicle while the sun beat down on the roofs.
I doubt Toyota had as an elaborate system or factory installation.
This looks like an aftermarket product modelled after the British roofs.
It wouldn't be too hard to fabricate your own, but piercing the roof for mounts or portholes would be cause for water ingress unless carefully fitted. My two-cents.