What species of anemone?
Their shape, color and overall behavior is primarily related to light. First thing in the AM they will naturally be smaller and less "robust" much like soft corals do when the light first comes on in the morning. As the day progresses, they should get fuller.
Feeding is also dependant on species and what else is in the tank. Except for a BTA, I would urge against feeding the anemone if you are generally feeding the tank for fish. Even if a BTA, feed sparingly and infrequently.
What size tank and lighting?