Yesterday I found about the 1914 Christmas truce between German and British 5 months into WWI.
I think this shows the true meaning behind Christmas. Though this was not repeated in WWI. In my opinion one of the most important event of WWI. Not just because the tradition of Christmas trees were being shared by Germans to British, but because despite differences these men learned to share in love and joy.
Here is a documentary on it:
https://www.youtube.com/watch?v=9v35BUhUHg8
While the event may be true, the picture looks like a cartoon drawing and not an actual photograph. Note the detail after zooming.
By the way, my great grandfather could have been there. I won't mention which side.
It probably started out as a photograph but was touched-up which was common practice in the newspaper business well into the 1960s. The above photo is a more extreme case of the practice.
Photos that were published in books were sometimes given the same treatment.
Yep, you used to notice black or white lines outlining people or equipment where some contrast was needed. I forget the terminology for the particular effect. Very common in the 'Teens thru the late 40's.