It describes itself by saying that "The objective of this campaign is to educate non-involved people into an awareness of the criminal occupation of Palestine by Israel with the collusion of Europe and the USA." They hope to send a thousands of these postcards to world leaders by the 70th anniversary of the UN resolution to partition Palestine into an Arab and Jewish state.
A peek at the "postcards" show that when they say "occupation" they aren't talking about 1967. Their goal is explicitly the destruction of the Jewish state:
Now, David Gilmour shows that Roger Waters isn't the only member of Pink Floyd whose brain activity is comfortably numb. In a remarkably egotistical addition to the gallery, he simply posts a photo of himself wearing a T-shirt that shows that he supports the lies, bias and bigotry of both his former band-mate and the project itself:
Maybe someone will submit a postcard of the Roger Waters concert pig balloon with the Star of David. It would fit right in.
(h/t Slava)