Fred, when I pass a stranger in the street we may make eye contact and exchange 'mornings', 'lovely day' or other pleasantry that helps oil the wheels of the daily grind. We may bond for a moment over a moan about the rain but we connect, albeit briefly. This is normal interaction and for some people it may be the only social interaction they get all day - it is a boost to the spirit, a feeling of camaraderie and a sign that one has been acknowledged as a fellow person.
It may not be much but it may be a whole big deal.
If I pass a woman in a burka there is no eye contact as I cannot see her eyes. I have never yet passed a woman in a burka who acknowledged me in any way, even though I smile or nod. I do feel able to say 'lovely morning' as her attire is telling me - I do not converse with men I don't know.
I have discussed this with my wife this evening and she feels the same way, except she gets the message that woman in the burka does not want to know or acknowledge her.
This is very sad and if there is a burka wearing woman on AB I would love to hear her views on a strange man speaking to her in passing.
My burka wearing acquaintance is always with her husband and he does all the talking when we meet.