The focus of the photo isn't very good - the spots look sort of diffuse. If they look that way in real life, it isn't ich. When it first begins, ich trophonts will look very distinct, with sharp edges, like a grain of salt. In advanced infections, the fish's skin mucus will start to develop, making the spots seem to coalesce and look less distinct.
@Jay Hemdal I've asked the Tang several times to pose for a picture. It's just not listening.
Looking back at my 1st picture and this one, one of the fin spot seems to be in the same position.
Also, I noticed the spots tend to be very hard to see in the morning with lower light and even hard to see when I manually raise the lights.
After mid-day, they seem much more pronounced.
It could be the original fin spot never left, which would point more to a lymphocystis?