quay/static/directives/location-view.html

<span class="location-view-element" data-title="{{ getLocationTooltip(location, locationPing) }}" data-html="true" bs-tooltip>
  <span class="flag" ng-class="locationPing == -1 ? 'error' : ''">
    <img ng-src="{{ '/static/img/flags/' + getLocationImage(location) }}">
  </span>

  <span class="ping-tower" ng-class="locationPingClass">
    <div class="ping-sliver"></div>
    <div class="ping-sliver"></div>
    <div class="ping-sliver"></div>
    <div class="ping-sliver"></div>
  </span>
</span>