1. What makes it an effective image?
I like the lighting and the focus of not only the Clowns but their host anemone as well.
2. How was the photo/subject lit?
Looks like a camera mounted flash was used.
3. Does the image capture the personality or essence of the subject?
I believe it does. The photo is showing not only the fish but their relationship with their environment.
4. Is there any question about what the main subject of the photo is?
To me there is not. Although there are three potential subjects I think it is clear that it is about the relationship they share.
5. Is there anything that the Photographer could have done technically to make this a better photo?
I think there could have been improvements in the flash technique. I am a little distracted by the shadow of the Clown on the right. Makes it obvious that the photo was taken with a flash. The dark area at the bottom could have been avoided. The DOF pulls the eye back a little too far in the upper left corner. Focus of the fish themselves could have been sharper.
