Absolutely stunning photo!
Would I be cheeky to ask you how you had your rig set up? After an unsuccessful Mandarin fish dive myself (focus light packed up after I'd spent I don't know how long making a red filter for it!!
) I'd love to know how you got your shot...
What spotting / focus light were you using? Did you go for a red filter etc 
Having done MANY mandarinfish dives before myself, including strapping red celophane over my light, etc., I have discovered that it is VERY difficult to handle both lighting and focusing/shooting by yourself. Trying to spot an emerging pair of fish through your viewfinder is just plain tough!
I did two mandarin dives on this trip, the first "by myself" using a FIX LED light on low, during which I got NO decent shots, and the second dive using a much more "manual" technique, i.e., with the dive guide holding a weak flashlight behind his hand so that only a faint amount of light came through. The dive guide would watch for a "pairing" and when he thought one was beginning, he would grunt loudly and my dive buddy (Don Silcock) and I, who were shoulder to shoulder next to him, would try to find the pair in our viewfinders and focus on them as they rose from the rubble. Once they cleared the rubble, the guide was able to shine the full light (albeit still a pretty weak beam) on the couple and we had a second or two to try to focus and get a shot. On that dive, I got three "keeper" shots, one of which is the one above that started this thread. (You can see the other two keeper shots in the gallery at www.seattleyates.com .)
When you consider the "productivity" of my first mandarin dive on this trip vs. the second (ZERO vs. 3 keepable shots), the argument for having a dive guide handle the lighting is (at least IMO) pretty compelling. It was still lucky that I got the shot with eggs, but I'm not sure I would have gotten ANY good shots if I had been trying to do it all on my own.
Hope that helps!