It would appear that this Dragonfly has a web to assist it in capturing its prey.
Of course this is not the case as Dragonflies do not spin webs.
A habit of Dragonflies that I have observed numerous times this summer is that of returning time and time again to the same perch. I have found this habit to be very beneficial to the photographer as it has allowed me to scare the Dragonfly away during setup and then have it return to the exact same perch after a wait of only a few minutes.
I have noticed a marked decline in the number of Dragonflies with the onset of autumn.