Idmāj demands an identifiable primary and secondary aim. A poem may, for example, be chiefly about sleeplessness caused by separation while also communicating a complaint against the injustice of time.
The primary aim emerges from the context in which the words are spoken. The embedded aim is the additional intention conveyed through the very same image.
A successful embedding makes both meanings coherent. Simply crowding two unrelated topics into one line is not enough.