The prisoners
One of the first scenes shown at the beginning of the movie is that of the main leader's son standing in the sun, without a care in the world, while beside him stood a large group of prisoners, surrounded by men holding bows and arrows. When the son raises his hand, the men release a shower of arrows on the men, killing everyone instantly. The son remains impassive, not affected at all by what he had just seen. Through his reaction, the film portrays the warrior tribe as a cruel and ruthless one, not caring about the people they killed.
Killing a man
During her first battle, Mulan corners the enemy commander and is urged by her fellow soldiers to kill him as quickly as possible. Mulan hesitates for a moment but then decapitates him with a single blow. While the rest of the soldiers around her rejoice, Mulan looks in horror at the man she had just killed. The image of Mulan's horrified face is an important image in the film because it shows just how traumatic it can be for a person to take another person's life.
The aftermath
The film shows in a rapid succession multiple battles taking place after Mulan is named sub commander and then commander. These battles are not described as being glorious or heroic, but rather bloodbaths which cause a lot of pain and suffering. This image goes against the image created in the beginning about war and aims to show a more realistic image.
Cleaning out the name tags
After the battle ended, Wentai and Mulan sit on the bank of a body of water and clean meticulously the blood of the nametags taken from the bodies of the dead soldiers. Wentai tells Mulan he is doing this because he does not want to send them back the families of the deceased with blood on them, scaring them even further. The care with which the two clean out the nametags shows just important for them the memory of their dead ones and preserving it as best as they can.