I am not sure which species of Damselfly this is. The earlier stage of these are nymphs which live underwater, sometimes for several years. It has just emerged from the nymph which has crawled up the plant and then the skin splits open and the Damselfly appears. He pumps fluids around his body and he expands and his wings take shape. It takes a while for this to happen and he doesn't really get his true colours till his new skin/shell has hardened.
If you look to the bottom left you can see his old skin from which he has just emerged from.
