Dancing dirt into the snow Lyrics

Lyric discussion by LoveThyEnemy 

Cover art for Dancing dirt into the snow lyrics by Missy Higgins

I think its about an insecure person that she was close to or someone who was very deeply hurt and suffering a kind of depression. And because of this they tend to block others out and put on this tough face. however, i think missy knew the person before they became like this and is trying to explain that she can see that they are hurting and almost going backwards. the dancing dirt into the snow i think refers to not being happy and maybe trying to be rid of the snow as its a sign of change?! I'm not sure if i'm on the right track but thats what i get out of it.