Through out the first chapter of genesis the difference between good light and dark, man and woman and other things were established from the beginning. This in turn established a dichotomy of many things from animals that could fly to those that could walk on land. This in a larger picture I think put life into a view of binary as in there is only left and right or up or down. This represents choice in where you get to pick which of the two binary choices in which you want to represent. it also shows there is no gray are really in life it is either you sacrifice one for the other.
I also believe that they are there to represent the different levels of power that there are. With God being the head of everything and the all power being there is. the angels would be next when the writing refers to, “our” it is only right to assume the other people would be the angels. Then humans being next because they were mad to rule over all the animals on the earth that were on land, air and sea. Animals being the bottom rung. It sets the tone of human supremacy in my mind for higher beings on earth and why we as humans have developed so much beyond what we understand.
