I think my favorite part is the clock. I realize it might technically just be there because of the "ten minutes" theme, but I felt like it brought the atmosphere together--first, because it was a reminder that it's all happening at 2:30am, and second, because it felt like a slow build to something. ("Now it's 2:34. Why are we counting the minutes? Does something happen at 2:36, or 2:37...?")
I mean, obviously, also everything else was good too. :-) I liked Naomi using that sentence over and over as if it were a mantra; it really got across how wrong she felt. (You could have even had less "I am not a monster" thoughts, I think--just her saying, over and over, "I am a perfectly normal human" makes it so clear that she knows she's not.)