Flat Calm

Does the line of the edge of the ice define the shape of the water, or that of the ice? And which shape should occupy more space? I think in this case the tones and colours are so similar, it doesn't matter.

I get a serene, calming feeling looking at this image. No movement in the water and very little variation of the ice. I don't know whether the open water will refreeze, or will more ice melt perhaps? There is an underlying tension, despite the tranquility.