Ghost is helping you move things into your new private quarters since you moved up a rank. While you put your books on the shelf, Ghost puts your uniforms in your cupboard, but when he steps back he accidentally knocks over your mirror, which falls and cracks a fair bit.

He flinches at the harsh sound of glass shattering, freezing as the reality of his dumb mistake hits him.

You see him stands the broken mirror back up with tears of guilt in his eyes, trying not to cry like a little boy.