Photographs have their own power over time and space. Inside a photo, there might be a world pretty different from the viewer's world, and always from another time.
Simultaneously, as the artwork is experienced, the photograph projects its reach into the present. This is also what happens inside these images: the block of ice has preserved a moment in time, but as it melts, time catches up with the contents and it returns to where it originally were, where it is supposed to be.
And just as the conveyed contents of an image has its own nature when told through a photograph, the light inside the space of an ice block reveals its subject differently than if it had been, say, a still life in air.