Why doesn't the light pass into the glass and reflect off the back?

As she moved the cell phone to the right, the light reflected off something.

I saw the light reflect off his head, so he must have been bald.

And some of those qualities may be reflected in his life off the field.

The poor form of the team was reflected in financial disappointment off the field.

However, much of it was also reflected off the blade and lost as heat.

The light reflected off a metal object on the bed.

It will cut down on the sun's glare reflecting off his face.

Earth turned cold because so much sunlight was reflected off the clouds.

The light from the bright street outside was reflecting off his scalp.