As I was looking at this photo of mine from SF, I noticed something about the building with the graffiti on it- if you look at its roof, you’ll notice that on the north slanting face, there’s a bank of windows that reaches from the floor to the ceiling.
That type of window was built for a very specific purpose and they are almost always on the north side of a building.
You’re looking at a photographer’s studio from the late 19th through early 20th century, where that large window was the only light source for portrait sittings! They faced north, because, at least in the northern hemisphere, that is the only direction that provides soft, consistent, indirect light, no matter the season.
I first learned about this when I was a teenager and the salon in Oakland, NE where I got my hair cut was in the old photographer’s studio. The owner of the building was the granddaughter of the photographer and she loved to explain how her shop had such beautiful light in it.
So, leave it to me to find an answer about San Francisco in Oakland.