I'll play up the lighting to make it look like they've been spotted by a flood light.
The True Mermaid will have a brilliant glow about her, were the False will have more subdued glowy bits like a deep sea creature.
I wonder how many have actually caught on that the True Mermaid only has 1 arm.
Tell me what you all think so far and please help share them around the web and help improve the number of supporters available. ^ _^