The word translated 'man' is literally 'of the earth'. If you change the word 'man' to 'of the earth', and to not use the pronoun 'he' but 'they' as God also speaks of himself as a plural being, 'let us make ...' this first being, created in God's image, is, as I understand this, both man and woman together in one created being.

As God is three beings in one, Creator, Word and Spirit, so 'of the earth' made in his image is three beings in one, body, word and breath and male and female in one being which God separates in order to be able to make a 'counterpart' for the first created being.