I am rarely outside at the right time of day to see this, since it’s on the wall of my workplace, early-to-mid-afternoon. But it’s quite a sight.
The building next door is a historic monument. The owners decided to build another building both behind and actually over it which is glass and steel, and which is what is casting these reflections.
The nice thing is, the enhancement also serves to make the brick building underneath much more earthquake-safe.
That’s the building — or, at least, the historic part — you can see reflected in the window.