It doesn’t look like Ick to me. Looks more like a wound. Could be a bite from another fish, but there are some bacterial or fungal infections that could cause that as well but I’m not an expert and couldn’t point you to what it could be.
If it was me, I would observe for a few days and see if you can see it either getting better or worse. If you see improvement then i would guess it’s just some kind of injury. If you see it getting worse I would look into issues that could cause similar symptoms like a bacterial or fungal infection.
Sorry I don’t have more of an exact answer. Hope this helps. Take care and happy reefing.