License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Karel Dujardin. Two sheep, one shown frontally in a reclining position with its legs folded underneath the body, to the right a standing sheep shown from behind in three-quarters view, a grassy field below them and beyond, ca. 1655. The Metropolitan Museum of Art.