Well, I think your angle is good... but I wonder about it's depth. It doesn't need a ton of light... but I'm thinking it would open more if it were higher up in the water column. Of course, you'd need more rock to do that, hehehe...
It looks healthy enough, nothing that says it's doing poorly. But some corals take a while to open all the way. 3 days isn't a long time... I'd wait until it's been in the tank a week, if it still hasn't bloomed out into a pile of bubbles you might want to get it closer to the lights.