Bozetto. Solomonic columns.
However, the vanishing point is low.
 
Original Prado modello. Solomonic columns.
Vanishing point is high up.
We view the steps from underneath
This is what you'd expect from a Solomonic design
 
Modello National Gallery. Doric columns.
We view the steps from above
 
"Cartoon" Ringling Museum. Doric column(s).
Follows National Gallery modello view.
This is what you'd expect from a design with Doric columns
 
Tapestry Descalzas by Jan Raes and Jacob Geubels.
I have reversed it for easier comparison.