I can't tell. Mine don't ever really have their mouths exposed like that unless flow is right on them. Even when pooping their mouths aren't that exposed.
It doesn't look like the polyps retracted due to stress or anything, otherwise the outer polyps would be pulled back as well.
Did it maybe have polyp bailout?
I don't see anything to suggest any really bad infections like brown jelly, so I don't think it is that.
Maybe it really is just agitated. Anything touch it? What is the flow like right there? How about lighting? Also double check your water parameters just to be safe. Every now and then if I do notice my Hammers acting grumpy, it usually means it is either time for me to dose or to do a water change.
My guess is that the sand is irritating it. The 2 upper heads seem fine but the 2 close to the sand are retracted my guess is the sand maybe try moving it away from the substrate Abit?