Apparently, the dragonfly symbolizes change, and change in the perspective of self realisation. The kind of change that has it's source in mental and emotional maturity and the understanding of the deeper meaning of life.
You can read more about the dragonfly and myths surrounding it here:
I was struck most by how still it was as it hovered, almost motionless. Still and present. It's attention wholly on the flower. A dragonfly lesson.