De l'autre côté du miroir. has many more of these retro-cards. Wikipedia also tells me this custom originates from Nantes.
Perhaps you recognize yours truly from this picture taken a few moons ago.
If you can't go to the countryside the muguet comes to you anyway, such is the magic of consumer society!
Wishing all of you good luck on this 1st May, with song interpreted by none other than Danièle Darrieux, who played the mother in the movie I mentioned in my previous post.