I think what you need is:
<div class="acenter">
<button type="button"
class="btn btn-default"
data-toggle="popover"
data-placement="right"
data-html="true"
data-original-title="Popover on right"
data-content="<img src='img/moment_images/seattle.png' alt='Seattle'/>Vivamus sagittis lacus vel augue laoreet rutrum faucibus.">
Popover on right
</button>
</div>