It's hard to say, because not many studies are done with cats. The folks over at Mental Floss mentioned doing a test of their own and finding that only some cats would acknowledge the optical illusions.
One problem is that some cats (like mine) just like the sound that paper makes when it crinkles and tears. If I put a blank piece of paper down, they'll act similarly. At least up until the point where they start shredding the paper.
It's also important to note how cats' eyes are different from ours, so they will perceive the illusions differently. Notice how their eyes aren't quite placed on their faces as human eyes are. That gives them 10% wider peripheral vision compared to humans.
Wired.com has a pretty neat explanation on how cats' eyes work. Basically they have more rod cells in their eyes, which makes them more receptive to light, which is what allows them to see in the dark better. They also refresh faster, which gives them better movement detection. The downside is that they have a more "washed out" sense of color.
Dogs and cats were previously thought to be colorblind, but really it's more of an almost red/green colorblindness. I say almost because they can still kind of see red/green colors, it's just that blue/yellow colors are stronger.
In the end, your guess is probably as good as anyone's. Until a proper study is done on it, it's going to be just a bunch of guesswork.