Culture is fractal, and happens on many different levels. And there are many types of stratifications of culture. And those stratifications can happen in multiple dimensions at the same time.
But culture can also refer to a larger conglomeration of smaller cultures, or components of smaller cultures.
Just like a meal or dinner from one place can have many different components, and be differently prepared from a meal or dinner of the same overall type from some other place. There are components that may be shared between them, and there might be components that are different. But even if you start out with the exact same components in both places, the end result may be radically different, simply due to the different methods and the different people involved.
In the case of DC versus Baltimore, it’s the larger scale differences that I’m talking about.