Reversals -- Light and Shadow

This is following up from bec's Table of Contents thread on the reversals topic.

I rarely use reversals as I tend to see both sides of the coin for any given coin. Question and Spread position can signal whether the card has a light meaning or a shadow meaning in the context. Sometimes, it has both: You tell the querent both the light and shadow as guidance.

However, when I use reversals the method of reversals that I tend to use is to have the upright position represent the 'light' meaning of the card and to have the reversed position represent the 'shadow' meaning of the card.

To borrow an example from Banzhaf on Thoth, if the 'light' meaning of the 2 of Disks is "Flexibility as the positive side of change", the 'shadow' meaning of that card can be "Instability".

While reversal meanings often or sometimes used by various tarotists are antonyms of the upright meanings, strictly speaking the concept of light and shadow meanings is different. Light and Shadow meanings are not opposites (i.e., the Shadow meaning is not an antonym of the Light meaning), but are two sides of the same coin.

Question...

Thank you, Rusty

This may be an "obvious" question, but my brain is functioning in "mud" mode today:

Is it the surrounding cards that alert the reader if the reverse card is to be read as a "shadow" rather than as the antonym? And for that matter, that reveal, or detail, the depth of the shadow?

Okay - more than one question...

Also, a direction a shadow falls is directly related to how light hits the object. I take it one reads the cards in the same way; the "light" card will give the "shadow" card its direction. Or am I being too literal?