I have not seen anyone answer your question so I will try.
Casey was furious with Ashton. When she grabbed her left wrist with her right hand, I feel sure this was a personal expression by her of "I'd like to strangle you with my bare hands," you meaning Ashton. Go back and watch the video, it's clear as anything can be. JMO. She has a murderous look in her eye at the point where she grabs her wrist, and she is staring into Ashton's back as if she could burn a hole in him. Casey's fury builds until she suddenly grabs her wrist.This I have no doubt is the Casey that Caylee saw just before she died.
http://www.wesh.com/video/21931324/index.html
Interesting too is that Casey's reaction to Ashton is so lightning quick, it brings up the possibility that this is how Caylee really died. She was strangled. There in the courtroom, Friday, Casey's telling us with her body language that she has a preference for strangling her victims. I'm not implying that Caylee was quickly strangled because Casey had the time to carry out Caylee's death exactly as she wanted. Casey may have restrained her hands, then put duct tape over her mouth and nose deliberately so Caylee would understand what was happening, as much as someone that young and that small could, and then Casey strangled her, unleashing all of her hatred on poor little Caylee. Casey would've wanted to see the terror on little Caylee's face. Casey is a monster, and indeed deserves the death penalty. The SA is on to strangling as the manor of death.
Why strangling? Didn't Lee tell Jesse that Cindy grabbed Casey by the throat during her and Casey's argument? Sleuthers, I think this IS the answer to how Caylee died. It fits so well, so easily. All the theories we've had....I thought pool, some thought trunk and so on, but this fits, and needs no explanation because one mother in this family has already allegedly grabbed her daughter and set the stage for her own daughter to do the same but with one huge difference. If Cindy grabbed Casey, it was only a symbolic strangling.