使用bootstrap内置类可以把图片套圆角、套圆、套白边：

<img src="http://placehold.it/125x125" class="img-rounded" >
<img src="http://placehold.it/125x125" class="img-circle">
<img src="http://placehold.it/125x125" class="img-thumbnail">

利用好bootstrap的布局能力，做出类似缩略图集的UI很容易：

<div class="container">

<div class="row">
    <div class="col-xs-3">
        <a href="#" class="thumbnail">
            <img src="http://placehold.it/125x125" alt="125x125">
        </a>
    </div>
    <div class="col-xs-3">
        <a href="#" class="thumbnail">
            <img src="http://placehold.it/125x125" alt="125x125">
        </a>
    </div>
    <div class="col-xs-3">
        <a href="#" class="thumbnail">
            <img src="http://placehold.it/125x125" alt="125x125">
        </a>
    </div>
    <div class="col-xs-3">
        <a href="#" class="thumbnail">
            <img src="http://placehold.it/125x125" alt="125x125">
        </a>
    </div>
</div>

</div>