It was previously considered to be in the public domain because it is a scan (or similar) by the Bibliotheque Nationale de France, but not everything scanned by the BNF is automatically in the public domain.
It is possible that this file is in the public domain for other reasons, for example because it was published a long time ago (anything before ca. 1900 is most likely ok) or because its author / artist / photographer died over 70 years ago and it was published over 95 years ago. In such cases, a new rationale should be applied, and a different license tag (see Commons:Licensing and valid license tags at Commons:Copyright tags) should be used.
If the file is not found to be in the public domain, it might be nominated for deletion (NOT by any automatic process, but manually).
See below for the previous rationale (not applicable anymore).
Previous public domain rationale, no longer applicable
Cette œuvre a été publiée avant le 1er janvier 1929. Son auteur n'étant pas connu, cette œuvre est anonyme. Elle est donc dans le domaine public aux États-Unis, ainsi que dans les pays où la durée du droit d'auteur pour les œuvres anonymes est inférieure à 95 ans après la date de première publication.
Légendes
La Matinée libertine ou les Momens bien employés, 1787 illustration