I think there's a bias in the US against this sort of thing that doesn't exist (or not to the same extent) in Europe due to the age of the cities/buildings.
In the US, a building from the 1700s is a historic artifact to be cherished, while in parts of Europe a building from the 1500s is just the local pub.
So, the US is often hesitant to modify these old buildings, but Europe seems to have more of a perspective of "it's a building, not a museum, let's give it new life by modifying it."
This is just from the perspective of me, from the US --- and I think these old/new buildings are really neat!
Huh, thanks for that perspective, I (US native) was firmly in the "how could they do this?!" camp, but you're right! When old ass buildings are all over the place it's probably much more pressing to figure out how to allow ongoing development and construction, vs. how to preserve the aesthetic of yet another centuries-old brick structure.
Edit to add: ugh I still can't get over how ugly and deliberately discordant it looks, reasonable takes be damned!
How do the floors in the upper structure handle the sloping incline of the geometric shape? Is there just a lot of closed off volumetric slivers between the planes of the floor and ceiling and shell, or is there only one or two floors, with the upper floor having a larger rising canopy?