Function queued_start_row 

fn queued_start_row(
    queued: &mut Vec<SessionMessage>,
    remove: &Value,
    row: SessionMessage,
) -> SessionMessage

The row a remove line draws, taking the attachment that named the press if one is waiting.

The attachment is what carries a multi-modal prompt’s blocks, its commandMode and the source_uuid the live row pairs with; the remove line contributes the position, the clock and the id.