These don’t move. Someone asked but I replied no. Will get pics of underside today.I think OP said these 2 move...sponges don't move unless its growing to reach somewhere and cabbage corals usually stay in the same place.
OP do you have gloves you could use to pick it up and take a closer pic of the underside and to see how thin they are?
Now if there are any new searches that say that, I will gladly go get some. But, I keep reading and seeing "Sarcophyton produce and release toxins such as terpenoids."They are not toxic... lol