Polyps not opening.....always a fun one to figure out! There are so many reasons....

By the pic, your polyps still look pretty healthy. Couldnt see any obvious pox, predators or irritators. One thing I might possibly see though is a film growth over your polyps, that may explain the sparkles. I would recomend blowing them off w/ a powerhead, or a good swish in the tank to see if any film comes off. A film on your polyps will stop them from opening.

If I am wrong about the film, which is hard to tell by the pic, I have a couple more possibilities-

These polyps look to be freshly fraged. As as tazzy stated, some polyps could have blown off. I have had freshly fragged polyps not open for 2 weeks, and be ok. I have also had healthy polyps just not take to the fragging and wither away, no matter what I did. Bad glue jobs are a very common issue with polyps not opening- the glue itself becomes the irritator.

Alkalinity is another possibility. If your alk is alot different than the tank you got the polyps from, this can play a roll in your polyps not opening. Diferences in alk and alk swings are known to adversly affect polyps, causing not opening and melting. If they survive a transition, they will not open till they have aclimated to their new tank parameters. Any way to find out the alk of the tank you got these from?

Lighting- As already stated, tubs blues (along with most other blues) are a lower light polyp. Freshly fragged/dipped polyps also apreciate a subdued lighting. Starting said polyps at the bottom, and somtimes even in a bit of shade is a good idea. After they aclimate to the new lighting, they can be moved up little by little over a period of time to aclimate to heigher lighting.

I know this info doesnt give you anything 100%, but hope the info helps you out. Polyps not opening is always a tricky subject, as there are so many causes of the issue. Good luck!