I've often wondered that. Have a look at Francis Frith old photos https://www.francisfrith.com/search - there's a real mix of things that you can understand, like tourist sites and so on. But there's also an awful lot of street scenes, which are just street scenes. I guess a lot of it was...
I guess that takes me back to my query of 'why the question mark?' - which does make it look as though maybe you are a little unsure. When you're obviously not!
I think she must have been deliberately seeking out a bit of dilapidation - maybe for some project or other. But yes, I hadn't realised quite how run down parts of central Brighton were at the time when I was roaming the streets all the time there.
We couldn't get in to Star Wars after queuing up those stairs/escalator for a mate's birthday treat - so we went to see Close Encounters of the Third Kind instead. Still never actually seen Star Wars!