Across a row: one department's year. Down a column: one quarter's whole org. The empty slot is honest: Marketing did not exist in Q1, and the placeholder keeps that cell on the same scale instead of collapsing the grid.
trellis.row: 'dept' and
trellis.column: 'quarter', every (row, column) combination in
row-major order, column labels drawn once across the top and row labels
once down the left. Missing combinations follow
emptyPanels: 'placeholder' (default) mounts a
real panel on the shared scale with a quiet label, 'skip'
leaves a tinted blank, 'hide' leaves nothing. A 2-D grid
never re-columns responsively; panels shrink instead, so the grid's
meaning survives any width. Trellis is a premium feature; without a
license it renders with a trial watermark.