The propaganda effort in World War One, as many organizations and help groups were formed to help aid the War effort. I feel like at the time it was really the only way to get information out to the public besides newspapers
The poster's purpose is to draw a sympathy for the soldiers. In the war when the soldiers have down time there isn't much to do so many take up smoking to pass the time. It is saying we need cigarettes more than anything else
The purpose of this poster is to continue to emphasize the need for rationing food during this time. The word don't is capitalized to help emphasize this.

