Hi bwjoomlart
It's a custom HTML module to show testimonials, before editing the content of this module, you should disable the 'Default Editor' in Global Configuration of your site as this editor often strips out the html tags:
Then edit the li tag inside module content again, it should be like this:
<li class="col-xs-12 col-sm-2 col-md-1 active"><span><img src="images/joomlart/demo/testimonials/testimonials-1.jpg" alt="Donec ultrices quam at nunc molestie convallis. Donec justo tellus, euismod a ante at, dignissim feugiat nunc." title="Thornton Elias via Twitter" /></span><i class="fa fa-quote-left"></i></li>