And another said: I will follow thee, Lord; but let me first take my leave of them that are at my house. Jesus said to him: No man putting his hand to the plough, and looking back, is fit for the kingdom of God. (Luke 9:61)

Carmelite Nuns at work.

Benedictines going to work in the field.

The Carmelites at work are so cool, I love the enclosure veils! Where do you get these photos? They are great!
I found stuff all over the internet over the years. I got a few more of them covering their face I will post.
Approximately what year were those photos taken?
I believe they were from the 1930′s.
My goodness, and people today complain about the way Afgan woman wear the burka, which is considered a sign of opression.
I think they would be scandalized by Tertullian Veiling of Virgins: http://www.newadvent.org/fathers/0403.htm
The picture of the nun is from a series done by Boyer D’Agen in 1904: http://www.corbisimages.com/Search#pg=Boyer+D%27Agen&ri=HU041599&rin=10056599
The nuns cover their faces in these photographs because someone from outside of the community (the photographer) is present. They wouldn’t ordinarily cover their faces while working.