This card was selected because it shows a group of children, dressed as sailors, celebrating, and though the forces would have celebrated greatly, they would have also felt their losses the strongest, and there would have been much remembrance of colleagues that were no more.
The name "Maison a la Belle Jardiniere" actually translates to house of the beautiful garden. This may seem to have no connection with clothing, but for some reason it was chosen as early as 1824, when Pierre Parissot opened a shop selling ready to wear clothes, rather than ones you had to be fitted for and wait for them to be sewn. And his sign showed a gardener, watering flowers.
Now there is actually another "A la Belle Jardiniere", that is a brand of chicory coffee, by C, Beriot, also of France, but based in Lille, not Paris. This is the easiest way to tell which is which, though another way is to look and see if there are "succursales" with a list of other addresses - for these are branches, or offices, and that only applied to the clothing store, not the coffee.