Why doesn't parallax work in Vuetify?

Question

Vue.js

I went to vuetify and took a simple parallax example, but it doesn't work. And it doesn’t work not only for me, but also in codepen, where vuetify shows this parallax as an example. Who knows what's the matter?

<template>
  <v-parallax src="https://cdn.vuetifyjs.com/images/parallax/material.jpg"></v-parallax>
</template>