`@` as means argument to the template not property

blog-post-at-lookup.hbs

<div class="blog-post">
  <header>
    <Avatar class="blog-post__avatar" @user={{@user}} />
    <title>{{@title}}</title>
  </header>
  <p>
    {{@body}}
  </p>
</div>

how-to-think-about-it.hbs

function (@user, @title, @body) {
<div class="blog-post">
  <header>
    <Avatar class="blog-post__avatar" @user={{@user}} />
    <title>{{@title}}</title>
  </header>
  <p>
    {{@body}}
  </p>
</div>
}

react-equivalent-is-not-props-but-a-function.jsx

(user, title, body) => (<div class="blog-post">
  <header>
    <Avatar class="blog-post__avatar" @user={{user}} />
    <title>{{title}}</title>
  </header>
  <p>
    {{body}}
  </p>
</div>)