You enter a famous building, enjoy the architecture, shoot the art pieces that are inside, but because of time constraints (there are so many places to visit), you do not put attention to details. But making photographs has the advantage that you can come back to them later and study.
The fresco, a triptyque, is called Vers la Gloire (English: Forward Glory). It was painted by Jean Baptiste Édouard Detaille, a French painter known for his detailed military paintings. Having designed his paintings, he utilized original military uniforms and accessories of the Epoque. Wikipedia says that it was painted 1902-1905. However, in the resources of the Library of Congress, I found two photos dated 1890 showing this fresco, one with a statue of Jeanne d’Arc ahead of it. (Seemingly the statue was replaced later with the monument).
Making the photo, I was not thinking of close-ups. But still making cut-outs was possible on the computer.
I was not able to find any information on whether this mural reflects any specific battle. Still, it is showing a horse charge in times of Napoleonic wars (>>>).