I think this one by Seth is not quite correct.
One, the Taj Mahal is not a "big white marble house". It is not a house. It is a mausoleum.
Two, there were plenty of past works on which the development could have been based. His great-grand father, Humayun's tomb, in Delhi, could easily have served as a prototype - except for being in red sandstone. But then when Humayun died, the Mughal empire was not what it was in Shah Jehan's time!
The Taj Mahal is built on proven architectural principles. It is a design that has evolved.
The best specs are prototypes. And Shah Jehan would have seen plenty of those, as would have his architects.
Message: build your software on sound proven design principles. Successful designs - whether biological, architectural, or software - are evolutionary.
