I have noticed that when black people are crossing the road and I stop to let them pass, they often slow down and sort of swagger, presumably as a way to show their contempt for my courtesy.
I, on the other hand, always get out of someone’s way as quickly as I can, as a matter of common courtesy. And I don’t care in the least what color they might be.
This is showing up a lot these days, a sort of perversion of Ghandi's "passive resistance" to demonstrate their control of the pace of the interaction. This is called "an attitude," isn't it? It is kind of irritating, which is the object of the occurrence, to determinedly incite exasperation and anger on the recipient and hilarity on the part of the perpetrator.
The other manifestation is to sort of ignore you, to suggest that you are not recognized as even being worthy to be concerned about.