The package allows to issue commands to the robot by presenting it specially designed cards. While the first card allows to issue only one type of command (i.e. take a photo), the second one allows to issue four different commands.
You will need to print (no rescaling!) the cards.pdf file, cut out the cards and fold the 'operator' one. Presenting the pattern to the robot's camera causes it to publish the command on /socialCardReader/command topic.