On French trains passengers must move into the vestibule, where the restrooms are, to talk on their cell phones. They do this without exception, without fault. So mannerly, so polite the French.
They don’t, however, dance on the platform, as the SNCF railroad promotion above suggests.
Note that the boy isn’t wearing socks. Few young Frenchmen seem to wear socks, a subtle favor if you love every inch of the male body. (Of course, one loves some inches more than others.)