Often when someone has depression the sufferer can put a mask on for the public so that everyone thinks they are fine. Then when the sufferer is back in the sanctity of their own home they can take this mask off and wallow in their depression without anyone watching.
In my photograph I painted a happy clownish face onto my model to symbolise the mask put on for the public. Then I got the model to lie in the bath as if she was going to wash off the mask. I then changed everything in the image apart from the mask to black and white. This lack of colour is supposed to represent the model's depression (as when we are depressed the world can often seem less vibrant and colourful). The mask is still in colour as the model is wearing it for the public to pretend everything is fine.