Background modes

background-mode Edited as Rotated as Painted as
independent the selected monitor's entry only staggered (delay / N) per-monitor
mirror the representative entry (the one with no connector) synced (all change together) the same image on every monitor
spanned the representative entry (the one with no connector) synced one image across the whole desktop

CinnamonBgMode mirrors this key one-for-one, so a consumer can simply read its “mode” property. Only CINNAMON_BG_MODE_INDEPENDENT changes how monitors are matched to entries; mirror and spanned resolve identically — both fan the representative entry out to every monitor — and diverge only in the renderer, which paints spanned across the monitor union.