The problem with the rig itself would be that people have different heights. There would need to be a rig underneath that allows people of different heights to be level.
The goal of the art installation would be to make people aware of how small and insignificant we are. Even if you were the king or Queen of the whole planet and you lived for 700 years you would find you are insignificant, the whole earth is just a speck in the cosmos and our whole life is fleeting moment in time. Even the materials that make up your body are made almost entirely of empty space.
The mini museum would show you visually how even the entire galaxy is tiny compared to the universe and 85 years is short compared to the 13 plus billion years of the universe's existence.
You would be standing in a fake museum; only your head would be there. The fake mini museum shows you how grand everything is yet it is small and nested inside an art gallery. If it is the Tate modern then it would be the tubine hall.
The thought is nice and unlikely to become true but the main purpose of the thought was to make it easier for me to fall asleep, to make me stop thinking about things that make me worried so at that time it was totally constructive.