The psychiatrist Mary is mentally unstable (putting in mildly). She was more stable at the beginning of the treatments which is why her notes were typed and clean. As more patients died, it fed into her psychotic behavior, causing her to become more unstable. This is reflected in the change of her note taking.
There are several ways to take her comments about the mirror in her last statement:
1. She's referring to us. We are the ones that are watching her and she has become aware of it.
2. She's paranoid and thinks that people are watching her.
3. She's shizoid and sees her own reflection, causing her to think it's someone else.
4. All of the above!
ps: I haven't gotten the emails either.