Nesting children is also an anti-pure-render pattern.

AnotherAntiPattern.js

// Consider <Button /> is a pure render component
const AntiPureComponet = () => <div>
  Call me maybe?
  <Button><IconPhone /> Call</Button>
</div>

// When <AntiPureComponet /> renders, it creates a new child (by calling React.createElement) and pass to <Button />.
// This behavior forces <Button /> to re-render everytime.

// To Avoid this anti-pattern, we should create a new pure render component wrapping <Button />,
// like following:
import { pure } from 'recompose';

const WrappedButton = pure(() => <Button><IconPhone /> Call</Button>)
const PureComponet = () => <div>
  Call me maybe?
  <WrappedButton />
</div>