Duncan Sweeper?

[Haubfather07]

I am brand new to the hobby. Have my first coral, picked out by my wife, a Duncan. Was out and happy all day per normal (owned it about 3 weeks now) and then started acting very strangely! See photos, it’s expelling something from each of its heads. A couple of times so far for each. This normal? What is it? I took video if that might help identify better.
Thanks in advance!