A couple of things my mind keeps coming back to:
1. Her arm swing when she first comes in the elevator.
If that was yourself, it would be indicative about feeling up or good about some recent or impending experience or event.
For Elisa, maybe she'd recently met or spent some time (I don't necessarily mean sexual) with someone she liked, or she'd just had a positive experience, like interacting with one or more people on the roof, or she was on her way to meet one or more people that she liked, or she was looking forward to going to a speakeasy in a little while. Or the cocktail of drugs in her were affecting her emotions, and she was feeling up for no reason, except for the drugs.
Or maybe she's just come back from the roof, after finding a good way to off herself? When she is 3/4 blind without her glasses? Not.
2. No glasses, on the 14th floor?
Was her vision as bad as her behavior in the elevator would lead us to believe? Or was it impaired even further than normal by something in her? If her vision was as bad as it looked, it's really hard to believe that she would leave her room without wearing her glasses.
I'm sure I saw a news report that all her belongings were in her room, including her glasses and computer.
And I haven't seen anything to confirm the floor she was staying on. So what's she doing up there by herself?
3. The splayed hand movements.
They initially look really, really strange, even when considering her overly, and overtly, expressive nature.
So come on everybody, close your eyes, or turn off the lights, and make those motions yourself. Let's do it all together. And what are you doing? You're searching around in the dark for something. Glasses maybe? Room key/card?
4. Why did the maintenance guy go to the roof, climb up the ladder, lift the lid and look into the tank when there was a problem/complaint about water pressure?
He would probably have taken a flashlight too, because there wouldn't be enough natural light from the lid opening to see to the bottom of the tank.
It wasn't because the water was black or stinky. Those comments came up later, only after the body was found. Probably from people looking for a law suit.
It was initially reported that he looked into the tank because of the low water pressure issue.
In a hotel that historically has had complaints about low water pressure?
In a hotel where one resident reported flooding 2-3 weeks before he looked into the tank?
Maybe there had been earlier events where someone had put something into a tank and it had blocked or obscured the outlet.
Maybe because he knew that people regularily went up to the roof and the lids on the tanks weren't locked (they are in big trouble with the health authority on that one, and the law suit will be successful).
If he was long-term, he would be aware of the graffiti, the bottles, and either knew residents who went up there or had encountered people up on the roof himself. And yet he told, or didn't contradict other hotel staff who told the police that the only way up to the roof was through a locked and alarmed door.
Or maybe because the maintenance guy had heard a rumour amongst hotel residents, or knew himself, that there was something in that tank.