Thanks, scinde_dawk, for your warm words!
From 1889 up to 1907, all
stamps issued for use in French Indochina colony were general
stamps show allegorical figures, the same
stamps issued for most
of the French colonies. In 1905, Paul Doumer, the governor
of French Indochina, demanded to have distinctive postage
stamps that show local culture. Hence, in 1907, a definitive set
of stamps featuring young women
of different Indochinese ethnicities was issued for use in the colony.
The set, contains seven different woman designs, was designed by
Puyplat based on real photos and engraved by
G. Johannet (which his name doesn't appear on the
stamps). For years I try to find the original photos used to design these
stamps and until today, I found five original photos out
of the seven designs. Here they are:
Lao Woman from Province Houaphanh (My postcard is a colourised one. The original PC is
of course B&W):

According to Michel catalogue this stamp shows a Tonkinese woman (today in Vietnam) but I think the women in the photo are Khmer [Cambodian], not from Tonkin:

Muong Woman from Tonkin (Today in Vietnam):

Khmer Woman:

Woman from Annam (Today in Vietnam):

I still didn't find the original photos used as models to design the following two
stamps:
Annamite Women:

Khmer Woman:

