gnu-social/plugins/ShareNotice/css/sharenotice.css

.notice-share {
    width: 24px;
    float: right;
}

.notice-share li a {
    display: block;
    width: 16px;
    height: 16px;
    background: url(icon-share.png) no-repeat;
}
.notice-share li.notice-share-twitter a {
    background-image: url(icon-twitter.png);
}
.notice-share li.notice-share-facebook a {
    background-image: url(icon-facebook.png);
}
.notice-share li.notice-share-statusnet a {
    background-image: url(icon-statusnet.png);
}
.notice-share li a span {
    display: none;
}