The one preview shared by every tab of the format pane: the selection's ANCHOR cell, rendered the
way the grid will render it.
Remarks
The pane applies live, so this is not a "what you would get" mock — it is the cell, re-read after
each edit. Only the VALUE is ever substituted: a cell holding text (or nothing) previews
SAMPLE_VALUE instead, so the Number tab has something to format. The style is always the
real one.
The one preview shared by every tab of the format pane: the selection's ANCHOR cell, rendered the way the grid will render it.