Stage or Separation cards

In the Rider-Waite tarot deck certain cards appear to be set on a stage.

I am continuously in awe of Pamala Coleman-Smith. I look at these cards for many hours each day as a professional reader, and I am still learning and noticing new details.

One concept I am still exploring is the “stage” or “separation” cards. Those cards that seem to be set on a stage. There are certain core cards where it is very clear with a double line, and others where it appears intended.

Wands; (2), 4, 9, 10

Cups 2, (5), (8), (10), page

Swords 2,(4), 5, 7, (9)

Pentacles 2, 4, 6, 8

Where () indicates it is less clear than the 2 distinct lines.

I don’t have a clear and single answer on this, rather several concepts I am still exploring.

Are these cards “framed” ?

I wonder if these cards are being marked as significant. It may be they are key cards in each suit- cards that we need to pay extra attention to in a reading. The stage is to draw our attention to the card in a spread.

It may be these cards have a particular occult knowledge that I am not aware of, codified information. I am aware there is much information regarding astrology and the kabbalah with in the deck- two areas of study I am less focused on.

The stage cards may be a reference to “key” cards with a meaning that is still hidden to many, or as yet not re-discovered.