ImageURL is the absolute URL the listing's headerImage now points at. The image is REFERENCED, not copied — it stays in the org's studio output bucket, so removing it there empties the storefront tile.
Slug is the product handle the image was attached to. It IS the asset's design field — that equality is the whole join between the studio and the catalog, which is why an asset with no design produces no storefront result at all.
Status is one of "published" (the product image was set), "not_configured" (no commerce edge, no store provisioned for the org, or a token that is not admin on the store — a fail-closed no-op) or "failed" (commerce answered and errored). None of the three fails the transition that produced it.
Store is the commerce store id the image landed in, resolved for the org mid-call. Present only on "published": a result that never got that far carries none.