Messages from pin-up

"Pin-up" is a term that refers to images of people, usually women, who are considered glamorous or sexually attractive. These images can be in the form of drawings, paintings, photographs and posters. The practice dates back to at least the 1890s but was first attested in English language only in 1941. Pin-up models could appear on postcards or lithographs as well as cut out from magazines and newspapers. Based on the SMS messages received from "Pin-Up", it seems like they might be offering some kind of service where users receive codes via text message for authentication purposes perhaps when logging into an account online or making purchases through their platform. However without more information it's difficult to say for sure what exactly this company does beyond sending these verification codes over SMS messaging services.