Tintoretto would use miniature models to make a mock set-up of the scene he wanted to paint, then study how the light fell across the figures, and the relationship between the figures to make his painting more realistic. It was a method similar to how artists even today will use wooden models to help them with the intricacies of human anatomy.

I think if TIntoretto was able to recreat this painting today that we would see some very fantastical changes. Assuming that he was literate in the digital mediums available, the amount of detail -- something that he prized in his works -- that he would be able to put into his art would have been vastly greater. Tintoretto was also a prolific artist, and digital mediums would have allowed him to create his works faster, so I think that we would have seen the 500 works that he managed to create using oil and canvas probably tripled.