Here is a visual representation of the standard thumbnail layout
Once the viewport reaches the small size, the layout should switch to this design:
Bootstrap only shrinks the container by default, as demonstrated in this jsfiddle: http://jsfiddle.net/32o4kses/
<div class="row">
<div class="col-sm-6 col-md-4">
<div class="thumbnail">
<img data-src="holder.js/100%x200" alt="100%x200" style="height: 200px; width: 100%; display: block;" src="http://placehold.it/241x200" data-holder-rendered="true">
<div class="caption">
<h3 id="thumbnail-label">Thumbnail label<a class="anchorjs-link" href="#thumbnail-label"><span class="anchorjs-icon"></span></a></h3>
<p>Cras justo odio, dapibus ac facilisis in, egestas eget quam. Donec id elit non mi porta gravida at eget metus. Nullam id dolor id nibh ultricies vehicula ut id elit.</p>
<p><a href="#" class="btn btn-primary" role="button">Button</a> <a href="#" class="btn btn-default" role="button">Button</a></p>
</div>
</div>
</div>
<div class="col-sm-6 col-md-4">
<div class="thumbnail">
<img data-src="holder.js/100%x200" alt="100%x200" style="height: 200px; width: 100%; display: block;" src="http://placehold.it/241x200" data-holder-rendered="true">
<div class="caption">
<h3 id="thumbnail-label">Thumbnail label<a class="anchorjs-link" href="#thumbnail-label"><span class="anchorjs-icon"></span></a></h3>
<p>Cras justo odio, dapibus ac facilisis in, egestas eget quam. Donec id elit non mi porta gravida at eget metus. Nullam id dolor id nibh ultricies vehicula ut id elit.</p>
<p><a href="#" class="btn btn-primary" role="button">Button</a> <a href="#" class="btn btn-default" role="button">Button</a></p>
</div>
</div>
</div>
<div class="col-sm-6 col-md-4">
<div class="thumbnail">
<img data-src="holder.js/100%x200" alt="100%x200" style="height: 200px; width: 100%; display: block;" src="http://placehold.it/241x200" data-holder-rendered="true">
<div class="caption">
<h3 id="thumbnail-label">Thumbnail label<a class="anchorjs-link" href="#thumbnail-label"><span class="anchorjs-icon"></span></a></h3>
<p>Cras justo odio, dapibus ac facilisis in, egestas eget quam. Donec id elit non mi porta gravida at eget metus. Nullam id dolor id nibh ultricies vehicula ut id elit.</p>
<p><a href="#" class="btn btn-primary" role="button">Button</a> <a href="#" class="btn btn-default" role="button">Button</a></p>
</div>
</div>
</div>
</div>