I got the D part from the leader survives from (D)emocracy, the part I thought was a bit dubious was A film meaning A mist.
I can only see that they are trying to say that a film on a surface is a fine mist maybe. A mist is a vapour like a cloud or fog.
Granted, it would become a film of water when settled as maybe dew on a leaf or condensation on a window, but it would no longer be mist. But then again, it is a well established saying that the windows have misted up. I will now shut up. Goodbye