As it is not a requirement of the Muslim faith to so do, then it must be that the individual has no wish to be part of our reasonably free society.
I make contact with everyone with their faces exposed, a custom over here which is called good manners and far removed from countries that impose it, mostly patriarchal closed societies, on their womenfolk where the females are considered second-class citizens without the equal rights and freedoms of their menfolk.
If these women wish to cover their faces then they should stay within their own narrow societies, as they do not seem to want to mix freely and openly with ours. Muslim men do not wear a veil or mask, so are they to be considered less devout?
A record of men wearing masks - mandatory - in this country was at Pentonville prison during the 18th and 19th centuries, thankfully now left as a footnote to our distant past.
It's time for these women to start moving into the 21st century with their faces uncovered.
Edward Murphy London N5