410 Gone
The default. The status tells browsers and crawlers the resource is intentionally unavailable, unlike 404 which suggests a mistake. Search engines drop 410 images faster than 404s. Sites embedding the URL get a clear signal in their logs.
Neutral placeholder
For layouts that break without an image: a plain placeholder in the composition’s aspect ratio, with no text and no branding. It answers 200 with a short cache lifetime so a later republish shows up quickly.
Never the last photograph
Whatever you choose, a withdrawn URL never continues to serve the withdrawn photograph from cache. The purge reaches every rendition at the edge before the status changes in the app.