To be honest, I do not get the high praise. Perhaps it's ok if you just not follow the narrative at all somehow. To me it made no sense at all.
Girl wakes up not remembering anything. Then there is a voice telling her "story". Is it coming from the clock? Or is it the voice, only we can hear, and not her? If the former - why is she so ready to believe that? Why is she not fazed out by anything in her room (which seems quite large compared to what you'd expect in such a facility)? I would freak out, at least from the blood on my toothbrush in these circumstances.
Even if we assume, that she does remember something about the facility, what comes next contradicts that: she is clearly unfamiliar with the layout at all. She is weary of the food. She does not know the names of other teenagers, who definitely know her (or at least of her) and are behaving relatively familiar with her. She does not know about the doctor, but yet knows her name somehow.
Even if we assume, that it's part of her condition - why is not mentioned to her outright by that voice? If it is for her, I mean. Because patient should know that. So that the patient would freak out a bit less. Although, in such a case, there would be a handler, that would be, well, handling her.
So, no. All of this does not make sense. Premise is interesting, but the way it is being delivered is sloppy at best. Camera work and general atmosphere is ok (I guess), but the narrative is crumbling from the get-go. Actor is also inconsistent: sometimes it feels natural, sometimes - overacting.