How does a piece of glass manage to reflect light from one side while remaining clear on the other?

The image on the video monitor dimmed slightly but remained clear and distinct.

But the strips in the floor remained clear and could be followed.

He had not lost consciousness; his mind had remained clear.

However, one image remained firm and clear, a human face that Paula knew only too well.

Conversely, if he had gone downstream, it would have remained clear.

The day was pleasant, the April sky remaining unusually clear.

She responded by letting the golems handle them, remaining clear herself.

Night fell with no perceptible change in the situation, the weather remaining dry and clear.

I thought the idea I woke with might go away in the dining car, but it has remained clear.