cmdui/frontend/src/blocks/user.css

.user-details {
    height: 50px;
    margin: 0 0 10px 0;
}
.user-details img {
    float: left;
    width: 50px;
    height: 50px;
    margin: 0 10px 0 0;
    border-radius: 5px;
}

.user-details .name {
    font-size: 24px;
    line-height: 50px;
}