Distribution is the channel fan-out this move triggered. Present ONLY on the move to published, the single edge that distributes — so its absence means no fan-out was attempted, never that one failed quietly. A fan-out that DID fail is present carrying its own honest status, because distribution never rolls the status change back.
Storefront is the catalog side effect, present only when a published Asset was product imagery — it carries a design and a kind of ecom, product or lifestyle. Absent for everything else, so absence reads as "not catalog imagery" rather than "the catalog failed".