This pulpit, made between 1265 and 1268, differs stylistically from the pulpit in Pisa by the same artist, Nicola Pisano, because Siena’s is less classical and slightly more gothic in style. The main difference between ‘classic’ and ‘gothic’ in this case has to do with the loss of composure in favour of more expressive actions and figures.
The artist no longer searches exclusively for formal harmony, but he also wants to communicate the intensity of a shared sufferance: the sentiment we call ‘pathos’, or rather, the act of sharing the pain of others.
The terms ‘classical’ and ‘gothic’ have always been considered antonyms: the first term means the expression of beauty without adding anything else to it; the second term means the use of the deformed, and even the grotesque, to express sufferance or pain.
This stylistic component, taken from the gothic, usually means “gothic pathos”: this is what we find when looking at the pulpit of Siena. It is also present in the previous works by Giovanni Pisano. The gothic style was also used much more in Siena than in any other Tuscan city.
If you compare The Nativity scene in this pulpit with that of the one in Pisa, you'll notice that in Pisa, the Nativity is depicted in a much more clear manner, with a sense of harmony and overall order. In the pulpit in Siena, the scene is much more confused, but also much more complex and virtuous: the figures have taken up every inch of free space, and they are depicted in every kind of pose, gesture and facial expression.
The Siena pulpit is also more complex for its physical structure—it no longer has six sides, but instead, eight sides. The panels are no longer divided with columns, but instead with statuettes, which give the pulpit a more continuous feel figuratively.