Optical deference in and out of water.

The two photographs are of the same Brown, notice the 5 dots under the eye. 

In the  "Aquarium" shot as I'm calling it notice how much
thinner this Brown looks from the one below.

In this out water shot, notice how much wider this Brown looks. 
Yes, the net gives a sense of  scale, but the water refraction
bends the light and reduces the size.

These photographs were shot with a Pentax W90.