I agree with necco. I'm inclined to think that she was not in her right mind in the surveillance video, and that this could be due to illicit drug or medications she was on.
Again, an expert on the behavior of people on drugs thought her behavior consistent with ecstasy use:
http://blogs.laweekly.com/informer/...s_ecstasy_strange_behavior_trinka_porrata.php
And her "best friend" in Vancouver also thought she seemed drugged in the video:
Elisa Lam's killer suspect - YouTube
And then there was the body language expert who thought she moved very quickly from confidence, to anxiety, to playfulness and then to preening in the mirror:
http://www.bodylanguagesuccess.com/2013/02/nonverbal-communication-analysis-2313.html And he notes that drugs are one possible explanation for her unusual body language:
"...although at times she displays some anxiety, there is no indication of fear. There is definitely an element of play present here. It is of course also possible that narcotics are influencing her behavior."
I agree with Futz that some people commenting on other sites are denigrating Elisa, and that that's a disgusting thing to do, but that's not happening here. We just want to figure out what happened,so that whoever killed her (if it was not a suicide or an accident) pays for it dearly.
The toxicology report should tell us more. When it comes out, I'll definitely reconsider this issue of whether drugs or medications had something to do with this. But it seems irrational to me to rule out drugs or medications as a possible contributor before the toxicology results come in.
For now, I think the idea that she was being affected by drugs or medications, and that this made her confused and a vulnerable, that she encountered a predator some time after the video was taken (though it could well have been someone she had met before) and that she was then assaulted, killed and disposed of in the water tank fits the facts of the case, as we know them at present.
But there are other plausible theories as well. We need more facts to decide which one is right.