1-based visual index (top-left = 1, reading order).
Layer title for the subplot, or empty string if not available.
Display labels for the subplot's layers, one per layer (e.g. Scatter Plot), not the raw TraceType values -- the dialog prints these
verbatim. Figure.getSubplotSummaries maps them.
True if this is the subplot the user is currently focused on.
Summary of a single subplot in a multi-panel figure, used to give users an at-a-glance list of what's available before they navigate in.