confusion about properties and methods

I think there is a little mistake on this file :
2-ui/1-document/01-browser-environment/article.md

line 25 :
```
// global functions are accessible as properties of window
```

It should be a methods instead of properties no ?

full code :
```js run
function sayHi() {
  alert("Hello");
}

// global functions are accessible as properties of window
window.sayHi();
```