Here we have the last clue, and it is the universal image of Remembrance Day, the flower which bloomed so freely on the fields right across Europe, covering the unknown graves of all those wasted lives.
If it had not been for the war, all the upheaval of the ground through the bombings and blowings up and trampings through the mud then it is unlikely that the poppy would have become its emblem. For the poppy likes nothing better than disturbed soil, and if the soil lies compact it can wait decades until something does break the surface and let it free.
Another reason that the poppy commemorates the loss of life is that it is a very ephemeral flower, its petals tumble to the ground with the slightest provocation, and seldom last but days. This card even says that "the poppy is at its best for a few hours only"
Now I have done a bit of research and though there is no month given for the issue of this set I have traced it to May 1939. The reason behind that is that the index of the Cigarette Card News gives it as a New Issue reported on page 155. Now I do not have that page, I have March 1939 which ends on page 128, and June 1939 which starts on page 177. It seems to me that 155 is closer to 177 than 128 so it stands to reason that it must have been in May 1939. If anyone does have a May 1939 then MAYbe they could have a look and confirm. A scan would also be of use, please!