[Hemidakota]

Anthony, I highly doubt that was a idiom here but a simple observation of what was seen. Even within Genesis when the creation the missing plurality on the usage GOD versus GODS created man. Even Jospeh Smith noticed this when he was correcting the Bible mistakes.

I shall comment on the very first Hebrew word in the Bible; I will make a comment on the very first sentence of the history of creation in the Bible -- Berosheit. I want to analyze the word. Baith -- in, by, through, and everything else. Rosh -- the head. Sheit -- grammatical termination. When the inspired man wrote it, he did not put the baith there. An old Jew without any authority added the word; he thought it too bad to begin to talk about the head! It read first, "The head one of the Gods brought forth the Gods." That is the true meaning of the words. Baurau signifies to bring forth. ... Thus the head God brought forth the Gods in the grand council.

I will transpose and simplify it in the English language. ... The head God called together the Gods and sat in grand council to bring forth the world. The grand councilors sat at the head in yonder heavens and contemplated the creation of the world, which were created at the time. (TPJS, pp. 348-49.)

The plural pronouns in this indicate very clearly that God was talking to someone else:

"Let us make man in our image." The question has been asked, "To whom was God speaking on this occasion?" The answer has been provided by God to Moses in another scroll:

"And I, God, said unto mine Only Begotten, which was with me from the beginning: Let us make man in our image, after our likeness." (Moses 2:26.)

The "Only Begotten" of God was the pre-earthly Jehovah, who came to earth as Jesus Christ. Thus, God the Father was speaking to Jesus Christ on that occasion.

Genesis 1:26-27

The terms "in our image" and "after our likeness" indicate that God had bodily parts just as man does. This truth has been taught by many other righteous Christians (meaning the followers of Christ).

The Church believes that “God himself was once as we are now, and is an exalted man, and sits enthroned in yonder heavens! That is the great secret. ... If you were to see him today, you would see him like a man in form -- like yourselves in all the person, image, and very form as a man; for Adam was created in the very fashion, image and likeness of God, and received instruction from, and walked, talked and conversed with him, as one man talks and communes with another.” (TPJS, p. 345.)