The subject matter is mainly puzzles, optical illusions or magic. Two illustrative pages are shown, along with the album itself.
The puzzle is to open the piece. It advertises M.C.L. AND REPETITION LTD. The outer surface also includes the words BRITISH ALUMINIUM BA-35. This will be the alloy type from which the puzzle is machined.
Cut the postcard into 3 pieces. Where does the 16th card go when the position of the two lower pieces are reversed? The postcard advertises Martinka & Co., a magic shop in New York City.