I have always known the dried flower pansies to be inside the card..
During WW1 silk postcards and handkerchiefs were bought as souvenirs by soldiers who were serving on the Western Front. Local French and Belgian women embroidered the different motifs onto strips of silk mesh which were sent to factories for cutting and mounting on postcards. There were two kinds of cards, one was a piece of embroidered silk mounted onto a card and the other was two pieces of silk sewn and mounted to form a pocket to contain a message or a silk handkerchief. It is an example of an industry which appeared as a result of war and must have been a useful source of income for families in France and Belgium.