In the context you provided, the phrase birds fly far overhead" could symbolize people who have the freedom to explore and travel the world, experiencing different cultures and perspectives. They have the ability to soar above boundaries and limitations.
On the other hand, the phrase "those of us whose wings have been clipped" or "those of us who dwell in unknown spaces, those of us who are beautiful beyond beliefs but that sometimes exist in environs too deep and murky to be seen from any stable surface" might represent individuals who face restrictions, obstacles, or marginalized circumstances that prevent them from fully realizing their potential or being recognized by society.
These metaphors can be interpreted in various ways, but they generally reflect the contrasting experiences and opportunities that different groups of people may encounter in their lives.
If you have any more questions or need further clarification, feel free to ask!