Regardless of the particular design of the façade, some space was always available between the two floors for shopkeepers and tradesmen to paint the name and nature of their business. If the buildings are still standing, albeit sometimes in a dilapidated state, very few painted signs remain and those that do are very faded. One of the "best" preserved ones is this rather puzzling ghost sign written in French.
These two words on their own clearly don't make any sense (agrandissement means enlargement). Since there is not enough space above or underneath, I suppose this ghost sign began on the façade to the left and extended to the one to the right. Unfortunately, as shown on the photo below, the former was completely rebuilt recently. As for the latter it still bears tiny traces of black paint but it is impossible to decipher anything at all. If I were to hazard a guess regarding the business advertised there, I would go for a photographer, who maybe also sold a couple of cameras to amateurs (given the limited solvable demand in town and the surrounding area, this can't have accounted for much)? Agrandissement can also be translated as expansion or extension but here I think it refers to photo enlargement.
Unless some old picture of the street emerges, I am afraid what the complete sign said will remain a mystery.
Location: Kampot / Pictures taken in December 2011