This painting is of a Roman soldier during the eruption of Mount Vesuvius in Pompeii, it is based on the remains found at the site of a Roman soldier in full armor. It's depicting the dedication of a professional soldier to his orders and duty post. As the civilians panic and scramble to find safety, this soldier remains steadfast and calm. I personally understand the ideals behind this painting and can speak from experience that as a professional soldier, you have already come to terms with your death and all that is left is to complete the mission. Whether it's storming a beach or simply guarding a post, even if it's hopeless.