The height and width is being set in the HTML
<div style="float:right;"><img alt='' src='https://www.gravatar.com/avatar/68f9ac8e4072d190f55933b97a98611a?s=100&d=http%3A%2F%2Fwww.gravatar.com%2Favatar%2Fad516503a11cd5ca435acc9bb6523536%3Fs%3D100&r=PG' class='avatar avatar-100 photo' height='100' width='100' /></div>
Either remove that, or change it to the appropriate width.
To do this with CSS:
.avatar {
border:1px solid #bbb;
margin:0px 10px 0px 0px;
float:left;
padding:2px;
width: 150px;
}
However, I don’t believe, the CSS will work until you remove the “height” and “width attribute from the <img> tag.