@media (max-width:720px) {

    div.simple_messenger_chat_block .thumbnail_block {
        display:inline-block;
    }    

    div.simple_messenger_chat_block .sender_nick {
        display:none;
    }

    div.simple_messenger_chat_block .sender_status {
        display:none;
    }

    html div.simple_messenger_chat_block {
        width:32px;
        min-width:32px;
    }
}