An observation is a selection. A lens admits some directions and not others. A notebook records some events and not others. A story preserves some causes while giving others no name.
Before asking what a pattern reveals, ask how the pattern was made available. What was filtered? What would this method fail to notice even if it occurred?
A missing entry can mean absence, ignorance, omission, or a broken instrument. Those are different states. Draw different marks for them.
MARGIN / THE TEMPTATION
Do not fill the hole with certainty.
The larger working image suggests that local traces may belong to wider structures. The blank does not supply the structure by itself.
Leave a deliberate unknown in the diagram. It keeps the page open to revision.