There are many different symbolic meanings for a dragonfly depending upon who you ask or what culture it is and many of those make it a great symbolic meaning for a dream circle. The primary reason I chose the name was the personal meaning I see as I watch them so deftly maneuver through the air - Carpe Diem - seize the day. Although they live longer than most people realize, being ground or water dwelling nymph for years, during their adult life they appear to truly live & experience their life which is a great lesson to learn. There is no analyzing, no debating, no weighing the pros & cons, they just do what they do and really seem to enjoy doing it. The reason for using that as a symbol for dream circles is due to my belief that everyone can further seize their day by building a relationship with their dreams or dream self. Seize the day by acknowledging the night. Regardless of your beliefs on where dreams come from, partnering with these nightly stories can help bring peace, order, direction & focus into your daily life.
There is much more that could be said about the Dragonfly, whether it be from cultural symbolism's to lessons they teach by observing their nature, but for now I'll leave you with this one link to symbolism. There is much more to be found if you are so inclined to look further.