Media the user saw last on the feed, as the app keeps them locally
(last_seen_media_ids: surface, time and the media ids). Local app state the
library does not keep, so a caller that knows it passes it and the search
screens thread it from the typeahead into the SERP.
Media the user saw last on the feed, as the app keeps them locally (
last_seen_media_ids: surface, time and the media ids). Local app state the library does not keep, so a caller that knows it passes it and the search screens thread it from the typeahead into the SERP.