library/XenForo/Model/Avatar.php

    protected static $_sizes = array(
        'l' => 192,
        'm' => 96,
        's' => 48
    );

		<div class="avatarHolder">
			<span class="helper"></span>
			<xen:avatar user="$user" size="m" img="true" />
			<xen:if is="{$user.isOnline}"><span class="Tooltip onlineMarker" title="{xen:phrase online_now}" data-offsetX="-22" data-offsetY="-8"></span></xen:if>
			<!-- slot: message_user_info_avatar -->
		</div>

<xen:avatar user="$user" size="m" img="true" />

.thread_view .messageList .messageUserInfo a.avatar img,
.thread_view .quickReply .messageUserInfo a.avatar img,
.conversation_view .messageList .messageUserInfo a.avatar img,
.conversation_view .quickReply .messageUserInfo a.avatar img
{
    width: 142px;
    height: auto;
}

.messageUserInfo
{
    width: 170px ;
}

.message .messageInfo,
#QuickReply
{
    margin-left: 186px !important;
}

	.Responsive .message .messageInfo
	{
		margin-left: 0;
		padding: 0 10px;
	}

		.Responsive .message .messageInfo
	{
		margin-left:  0px !important;
		padding: 0 10px;
	}