Here we see the infamous "Le mur de Boogair" or as it was more commonly known: "The Booger Wall ". Several aristocrats are shown here wiping their boogers on the wall.
The gentleman on the far left is admiring the booger wiping technique of his bearded friend while the man to the right is pointing out, to his young lady friend, some of the more famous boogers from such luminaries as: Noses, Arisnotle and Notrildamus.
Because of the unenlightened nature of this period, women were unable to directly participate in this ceremony and it was only after the booger revolt of 1710 that this practice was extended to include the general populace. Ironically, children, who show an uncanny talent for this sort of thing, were completely forbidden to participate at all.
Booger Walls were quite common throughout greater Europe up until the invention of sofas and recliners in the late 18th century.
-- Sister Randy