How do I handle my passive aggressive roommate?

Reddit, I have a roommate, when she is bothered my something she writes it in note form.. it bothers me because i"d rather her tell me to my face.

Example- my friend puked in our bathroom, I cleaned it up, I apparently did not do a good enough job so she cleans it herself then writes on the mirror in blue lipstick about how she is not impressed at all and how she cleaned it properly... my other roommates used her dvds, they did not put it in the proper casing, she leaves a note... and tonight she leaves a hand written note at my door saying: Hey! Can you please clean up the alphabet explosion in the microwave from your soup from last week! Thanks

Did I mention, this roommate of mine leaving notes... her room is always disgusting and messy and she doesn't wash her dishes right away.. she is messy herself.. wtf.. talk about calling the kettle black or whatever that expression is.

What do you suggest reddit? and from a curious/psychology perspective.. why do you think she leaves notes?