Answer
Reactions can appear on ordinary or scheduled requests, including failed generations. They add no notification, unread activity, hashtag vote or separate charge. Earlier messages are not backfilled.
The reaction matches the current request’s tone, intent and subject, with the applied hashtag description and up to two recent text turns as supporting context. Existing attachment analysis can help for attachment-only Text requests. An attachment-only media request without a prompt or hashtag uses eyes.
Attachment analysis or interrupted processing can delay a reaction. If classification is unavailable or uncertain, Hashchats uses a neutral acknowledgment.