In her case, she had lotion on her hands. Lots of the features aren't going to be used everyday but they can be handy on occasion.
I would rather have a voice command feature to operate the phone. That way you can keep it under a towel so it doesn't overheat in the sun (cause if you got to rock that much lotion, there must be some serious sun). Gestures make sense when they relate to a remote object that is the focus of your attention (i.e. a motion controller for a game). Waving your hands in front of a screen that is less than arm-length away seems less functional. I don't want to have to focus on my phone in order to answer/interact with it. Does that make sense?