This old postcard just goes to show that people have been fooling around with photos a hundred years prior to the invention of Photoshop.
This postcard is a spoof on how farmers used to take poultry to market. Live chickens would be loaded up into crates and packed into a wagon, which would then all be weighed on on a scale. The chickens would then be unloaded and the wagon weighed again. Payment to the farmer (or poultry dealer) was based on the difference. This method was certainly easier than weighing each chicken individually, although it wasn’t as accurate. The man in the front here is fiddling with the scale’s weights.