Yes, this is a postcard.  It measures 4″ x 8-1/4″ and exists firmly within its original Cello-wrap packaging.  It seems to have the endorsement of Macau’s Museum of Communications, and the QR Code will probably tell you everything, but it is also sponsored by Correios de Macau so it’s at least semi-official.  And all this leads up to:  no, we have no idea what the design is urging anyone to do.  Unused.  Grade: 1