This picture from Lee Niewoudt shows his Giant Condy Anemone (Condylactis gigantea) fully closed up with just a few tentacles sticking out, which is a normal feeding and often night time trait of sea anemones.
Sea Anemones are not the easiest things to keep alive and in good health in an aquarium. Here are the summary and analysis of the Host Sea Anemone Survivability Survey. The information here could help you to easily double the life span of a sea anemone in your aquarium.