Wow, this is very surrealistic! In this case, positioning the subject in the centre worked very well; it gives the viewer the sense that the shark is suspended. The gesture is very pleasing as well. I don't think it would have worked as well had you captured a profile of the shark: the way you took it shows more character and movement. I know it's hard with six inches of glass, but if you could have gotten the shark in focus, I think it would add a lot.
Chilling!!! Get me outta here, I'm scared!!
Yeah, the light coming in is great.