Each friend represents a world in us, a world possibly not born until they arrive, and it is only by this meeting that a new world is born.
As humans we respond to symbols. We express divine Beauty and insight in our art. If there is a preponderance of art depicting angels with wings, obviously this symbolizes something real within the collective consciousness. Angels appear to humans according to human capacity to accept and understand the appearance. The angels inspire, and that is what is left in our heart after an angel experience.