There was a reference to a diet but it wasn't the "only drink warm lemon tea for a week" type diets.. looked to me like she just had a lot of fruit & veg in her trolly that's all. Nothing wrong with that really.
I think the difference was Emma was exercising right from day 1 and kept up the exercising, where as the other lady was basically just being told if she taps her breasts enough times she won't want that bar of chocolate.. which may work for some people but it wasn't working for her.
The better approach would have been to get to the bottom of how/why she eats.. is it emotional etc, tackle that issue and then give her the tools to remind herself when she feels tempted of the bigger picture. Not tell her if she taps into her bodies magnetic fields she won't want to eat it. It's just unrequired mumbo jumbo. Maybe some people buy into it but she clearly wasn't buying into it.
And no exercise at all other than one dance session at the end? No one loses weight without exercising, not when you're that large. All she had to do was go for some walks. Not sure why Miss Mind Control didn't think of including that. Perhaps that's how she makes her money, doing it all via the mind. Wonder what her success rate is like.