example.html

 <div class="appgroup">
    <a name="Highrise"></a>
    <h2><a href="#Highrise">Highrise</a></h2>

  {% for highrise in site.data.highrises %}
  <div class="app">
  <a href="{{ highrise.link }}" target="_blank">
  <img src="{{ highrise.image" alt="{{ highrise.name }}" /></a>
  <p><a href="{{ highrise.link }}" target="_blank">{{ highrise.name }}</a></p>
  {{ highrise.description }}
  </div>
  {% endfor %}
  </div>

On line 8, you will need to close the double curly brackets for the "src" attribute:
<img src="{{ highrise.image }}" alt="{{ highrise.name }}" /></a>