It all depend on what you are looking for, in any way people don't live and dress as you see in American movies. In Brasil we don't speak Spanish, we speak POrtuguese and in Buenos Aires there's no beach, no coconut trees neither you can see the Andes.
You can discover an American tourist from a mile far away, nobody dress in such ridiculous way, neither American do inside the US.

As for poor and working class people, I am speaking of poor and not miserable people that is another story, there are very little possible combinations.
Poor people live in small apartment or houses with only a small room or two, so you have a simple bed, a table, some chairs, a stove, a refrigerator and a TV set, no more room to put anything else inside, how different can be an apartment from one place to another with so few elements, a simple bed is always a simple bed that has no more details to make it different.
The refrigerator and stove can be different depending on the fabricant and model. The same with the TV. A table is a table, in general made of wood, but of someone got a plastic or metal table then is a plastic or metal table.
The decoration can be very variable, it can have clean or dirty walls, painted with colour or not, if the person is some religious fanatic or not, his favourite football team or he doesn't care of sports, the rgion from where he comes and so on.
So unless there are some specific elements that can identify the inhabitant you have no idea where it is.
As for the architecture, there is or time to time there is, a goverment assitence to poor people and goverments builds apartments for poor people, of course much less of what is really needed. So you have thousands and more thousands of  apartment looking the same as other.
Next election, another politician, another plan and you have another series of thousand houses this time looking very different of the other. How the houses look will depend on the regional politician, the time, the plans of the burecratic goverment employyees, the profit over profit company that built it and so on.
If you look here looking at a building complex you can identify the politician responsable for the robery.

If you want to put some regional flavour to a poor class apartment interior just look in the US inside a poor class Mexican or Latino apartment and you have a lot of them.
Unless the apartemt has some details that can identify him as Mexican, Porto Rican, Brasilian, etc it will not make any difference.

Stupidity also evolves!