I have not personally seen a "low expression leopard" that was ACTUALLY a leopard. A few little signs to look for are that some have a faded head marking, and some have stripes going down their tails. A lot of people mistake normals for "low expression leopards", but once you have seen a lot of leopards you can usually tell right away. This is Spot:
Obviously the tail ringer isn't a leopard trait, but she is an excellent example of how the pattern will generally look. I've also noticed that baby leopards tend to have a sort of blue/green iridescence to them.
I never saw a photo of the snake. I had never heard of a "low expression" anything before so I was just double checking here. My initial reaction was correct.