This image refers to the folk tale "The Cowherd and the Weaver Girl" (牛郎织女). In this tale, hard-working cowherd Niulang meets the beautiful Zhinü, the weaver girl, who actually is a fairy. They marry, but the Goddess of Heaven disapproves and forces Zhinü to return to heaven and weave colorful clouds all day long. From then on they can only meet in heaven for one day a year - the seventh day of the seventh month of the lunar calendar. This is still celebrated as Qixi Festival (七夕).
Small text below the picture: 緣姻巧郎織女耕男 - The predestined marriage between the young weaver girl and the ploughman.
The poster is signed, but we could not decipher the characters.