That's a stark metaphor for a survivor and the situation he faces every day - a black spot on a white canvas. There's so much to think about in that phrase.
I wish there was some way to "turn off the pictures" - another powerful phrase. Unfortunately I don;t think we get to do that. But what we can achieve is to deprive the images of their power to cause us any further harm in the future. I hope being here will help you in that quest.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)