what does it mean?
The first PLM poster designed to promote winter sports appeared in 1900, the period when Switzerland and France were importing the first skis. The poster showed the lady skier dressed in an ankle-length skirt and low- heeled shoes. One year before the outbreak of World War I, Henri Lartigue noted: "Winter sports are not very popular in France." But in the postwar era all this changed quite rapidly. More than any other sport, skiing was a luxury, and the resort that would offer the greatest luxury and at the earliest date was Saint-Moritz. It attracted the wealthy in great numbers from all nations. 】
What does "PLM poster " mean?