This seems entirely strange. I've completed Ada's campaign 3 times, once of Normal and twice on Professional. Each time I got to the Puzzle Room, the image was always the Serpent.
Odd, I never knew it could be the fish or eagle. Just keep trying all images man!
Thanks to Xerofox for the romantically rambunctious signature!
Currently Playing: Halo: The Master Chief Collection
~ HALO IS LOVE, HALO IS LIFE ~