I've tried the cat eye before and always ended up with just a mess eye. Not with this eyeliner. It's smooth as silk and goes on as thin or as thick as you want it. The mascara doesn't clump and it isn't all over my face by the end of the day. Plus it makes my lashes look thick but natural.
I'm a little too old to think the poster is cool and I read somewhere that the guitar pick can be used as a stencil to help get the cat line - but this stuff applies so easily that you honestly don't need it.