JSFiddle - React, Tailwind, and code Playground
HTML
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/font-awesome/4.2.0/css/font-awesome.min.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<div class="container">
<div class='row'>
<div class="col-xs-2">
<a href="/url/to/object">
<img class="img-circle img-responsive" src="https://pensivepool.files.wordpress.com/2012/01/josef-albers-study-for-homage-to-the-square-silkscreen-print-80774.jpg">
</a>
</div>
<div class="col-xs-2">
<a href="/url/to/object">
<img class="img-circle img-responsive" src="https://pensivepool.files.wordpress.com/2012/01/josef-albers-study-for-homage-to-the-square-silkscreen-print-80774.jpg">
</a>
</div>
<div class="col-xs-2">
<a class="btn btn-default btn-circle btn-responsive" href="#link_to_add_new">
<i class="fa fa-plus"></i>
</a>
</div>
</div>
</div>
CSS
@import url('//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap-theme.min.css');
.btn-circle {
width: 30px;
height: 30px;
text-align: center;
padding: 60px 0;
font-size: 12px;
line-height: 1.428571429;
border-radius: 15px;
}
.btn-circle.btn-responsive {
border-radius: 50% !important;
width: 100% !important;
padding: 0 !important;
padding-bottom: 100%!important;
-moz-box-sizing: border-box;
-webkit-box-sizing: border-box;
box-sizing: border-box;
border: 0;
box-shadow: 0 0 0 1px #ccc;
}
.btn-circle.btn-responsive i{
height: auto;
max-height: 12px;
overflow: hidden;
margin: auto;
position: absolute;
top: 0;
left: 0;
bottom: 0;
right: 0;
padding: 0;
line-height: 1em;
-moz-box-sizing: border-box;
-webkit-box-sizing: border-box;
box-sizing: border-box;
}