Wow.... how can you tell? That's amazing! Are asymmetrical piebald domestic longhair's normally really tiny? When I got her from the SPCA she was really skinny because she had a litter of kittens in her first heat, and I don't think was fed very often by her previous owner. So I fed her so much and fattened her up, but she is still so small and tiny. Maybe she never fully grew after having kittens? I dunno.
Well, the markings on the left side of her face tell me that she's asymmetrical. Black and white cats are known as "piebald" if you want to get technical. And any non-breed-specific cat without papers that has long hair is a domestic longhair.
Your cat is so beautiful that I thought she deserved a fancy title.
How much does she weigh? She doesn't have the looks of any cat that I know of that's known for being small.
Oreo apppears to me to be a part Persian, with tuxedo mixed in. Many long-furred cats have some Persian in them. One of the ways to determine if any Persian is present is through her attitude. (I have one doll-faced Persian, all black, that has a different personality than my other fukids. Mopsy is laid back, is not demanding and very mannered. She is asleep most of the time.) Her small size, may be genetic. I have a white kitty (Blitz-Bug) with black spots on her coat, and she too is small (weighs about 4 lbs, and about 1 year old. Foxy is also a small, silver-white, part Persian.