Scenario: It's night, and a man is walking home. He sees ahead there is a woman going in the opposite direction as him. Knowing not to stop or approach her, but his presence makes her nervous. What would help further in this scenario if anything?
As a woman, seriously, just give me the bro nod to acknowledge that I exist but am not that interesting to you and keep walking. If you go out of your way to show that you aren't a threat now I'm thinking you're a threat, and if you pointedly ignore me now I'm wondering if you are actually far more interested in me than you should be but you want me not to notice.
Brief eye contact while acknowledging that I exist tells me you aren't afraid of me remembering your face but that you aren't being weird and staring or trying to hide from me.