The way he speaks makes her pause in her rage and irritation, letting her actually process the information she's getting from him. Her little bird is pulling at her hair, as if aware of her easily flaring temper, but she pays no attention to the bird.

Her eyes look up from him and around the beach(?), at other people helping each other out of water and complaining. Now she just looks extremely ruffled with annoyance and, while it isn't fair she's taking it out on the guy in front of her- he's the closest! She doesn't look as intimidating as she wants to be- not while soaked like this.

"Secure in what way? Secure that we can't get out? Or secure that nothing else comes at us?"

Because people keep falling into that lake, there are loud splashes, and that doesn't look too secure to her.