Can an attachment remain after the message containing it is deleted?¶

Yes. Once an attachment has been downloaded, cached, saved or copied, it may survive independently of the visible message that introduced it.

One delivery can create several artefacts¶

The application may keep a full file, temporary copy or thumbnail in separate storage. Device settings can save received media to a gallery, while a user may export it, open it in another application, forward it or copy it to cloud storage. Backups and linked devices can preserve earlier states, and recipients keep their own copies.

Deleting or unsending a chat entry usually changes a particular conversation state; it does not prove every downstream file and endpoint was erased. Automatic saving also means a surviving gallery file is not necessarily evidence of a deliberate manual save.

Reconnect the file cautiously¶

Preserve each surviving item with its path, size, hash, timestamps and source. Record whether it is a complete file, transformed copy, thumbnail or preview. Message and attachment identifiers, notification records, conversation sequence, exports and recipient evidence may reconnect it to the missing entry.

Visual similarity alone is weaker than technical and contextual linkage. If the association cannot be established, report the file's presence separately rather than asserting that the deleted message contained that exact item.