Looks like a Dendro. NPS corals will grow where other corals cannot, like in the dark. Thus, some people said they need shade or darkness. I have seen many post where people who scuba said they ave seen sun corals growing on top of the reef in the brightest sunshine. Here are some of my NPS in full light. You can see my Dendro in the center of the first photo. Six months ago it was a single head with the start of a small polyp on the side. In the second is one of my Black Sun Corals. He has gained 50% in the last 7-8 months. All are in full light.