x-person.html

<link rel="import" href="bower_components/polymer/polymer.html">
<polymer-element name="x-person" attributes="name image date_of_birth">
  <template>
    <style>
      .photo-container {
        height: 100px;
        width: 100px;
        overflow: hidden;
        border-radius: 100%;
        display: block;
        margin: auto;
      }
      .photo {
        width: 100px;
      }
      .info {
        flex: 1;
        margin: auto 10px;
      }
      .content {
        display: flex;
        height: 100px; 
      }
    </style>
    <div class="content">
      <div class="photo-container">
        <img class="photo" src="{{image}}" />
      </div>
      <div class="info">
        <h2>{{name}}</h2>
        <div>{{date_of_birth}}</div>
      </div>
    </div>
  </template>
  <script>
    Polymer({
      imageChanged: function(oldValue, newValue) {
        if (newValue === "") {
          this.image = "https://lh3.googleusercontent.com/-MsNtvUT1r64/AAAAAAAAAAI/AAAAAAAAAAA/uDXDAEKafXI/photo.jpg";
        }
      }
    });
  </script>
</polymer-element>