I see a lot of this sort of architectural gimcrackery around my neighborhood. It’s all EPS, expanded polystyrene foam. The illustration below isn’t all that different from sales materials of 19th century Victorian gingerbread builders, but they used factory-cut wooden ornament. (Sometimes wood posed as structural stone.)
I am especially taken with quoins; I have always liked them, the massive, protectors of the corners of buildings.
Adolf Loos knew it all, and denounced it with his characteristic verve in this essay from Ver Sacrum (1898), Potemkin Village. He was attacking the new Ringstrasse of Vienna, with its neo (pseudo) baroque splendor.
Yes, literally nail on! For these Renaissance and Baroque palaces are not actually made out of the material of which they seem. Some pretend that they are made of stone, like the Roman and Tuscan palaces; others of stucco, like the buildings of the Viennese Baroque. But they are neither. Their ornamental details, their corbels, festoons, cartouches, and denticulation, are nailed-on poured cement. Of course, this technique too, which comes into use for the first time in this century, is perfectly legitimate. But it does not do to use it with forms whose origin is intimately bound up with a specific material simply because no technical difficulties stand in the way. It would have been the artist’s task to find a new formal language for new materials. Everything else is imitation.