Answer
Wa `alaykum As-Salamu waRahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear questioner, we would like to thank you for the great confidence you place in us, and we implore Allah Almighty to help us serve His cause and render our work for His Sake.
Answering your question, Dr. Mohammad S. Alrahawan, Associate Professor at the department of Islamic Studies in English, Al-Azhar University, Egypt, states:
If you are convinced with the view that a woman is not supposed to show her face to non-mahram men, you must consistently do that with all people. An exception is made in case you are asked to show your face for a medical reason or for bearing testimony in courts or other similar reasons.
Allah Almighty knows best.