Fact: European cities have historic buildings.
Fact: Historic buildings sometimes need some preservation work, particularly on their lovely crumbling/dirty/pigeon-nest-filled facades.
Fact: It is generally agreed that scaffolding is kind of ugly. Certainly uglier than said lovely facades.
So when work is required on their landmark buildings, cities often put massive, life-size drawings or photos of said buildings on the outside of the scaffolding, which gives the appearance that the building is unblemished, if oddly two-dimensional.
The fancy scaffolding covering must cost a fortune. I realize that. They need sponsors to defray costs. Sponsors like to have something in it for them, though, and they typically demand something more than a nice handwritten card or a fruit basket.
Like a nice billboard--that would be a great way to thank them. Please don't notice that it is HUGE and takes up more space than the actual illustration/photo of the building. Please don't comment that the very presence of the billboard completely misses the point of the fancy scaffolding. Please?