It looks angry.
did it ever open up properly or has it been like this since day 1?
They are an easy coral once placed somewhere they like. If they’re in too much light, they get unhappy.
It will either stay like this and eventually the tissue will start receding or it will open up again and be fine.
if it opens up again, I’d give it a a few days and start feeding it mysis shrimp. I have had great success with Duncan’s and I think the trick’s to treat them like dendro or sun corals (NPS).