Nuns in a refectory

An albumen print showing an order of nuns eating in their refectory.

I have seen another print of this which wasn't cropped quite so tightly along its upper edge. There is a sign directly above the head of the nun seated at the centre of the upper table. It reads 'Dieu seul!' [English: 'Only God!' or 'God alone!']

Photographer and location unidentified.