duvida

 <style>
        .containerPhoto{
            position: relative;
            top:15px;


        }
        ul.thumb{
            margin-top: 10px;
            margin: 0 auto;
            padding: 0;
            float: left;

        }
        ul.thumb li{
            list-style: none;
            margin: 5px;
            width: 100px;
            height: 100px;
            border: 1px solid rgba(0,0,0,.2);
            overflow: hidden;
            bottom:0;
        }
        ul.thumb li img{
            width: 100%;
        }
        .imgBox{
            background-color: white;
            float: left;

            margin: 5px;
            width: 500px;
            height:500px;
            border: 1px solid rgba(0,0,0,.2);
           object-fit: cover;
        }
        .imgBox img{
           max-width: 100%;





        }


       </style>
       <div class="containerPhoto">
       <ul class="thumb">
           <li><a href="painel/php/<? echo $exibe["photoescortthumb"];?>" target=""><img src="painel/php/<? echo $exibe["photoescortthumb"];?>"></a></li>
           <li><a href="painel/php/<? echo $exibe["photoescortone"];?>" target=""><img src="painel/php/<? echo $exibe["photoescortone"];?>"></a></li>
           <li><a href="painel/php/<? echo $exibe["photoescorttwo"];?>" target=""><img src="painel/php/<? echo $exibe["photoescorttwo"];?>"></a></li>
           <li><a href="painel/php/<? echo $exibe["photoescortthree"];?>" target=""><img src="painel/php/<? echo $exibe["photoescortthree"];?>"></a></li>
           <li><a href="painel/php/<? echo $exibe["photoescortfour"];?>" target=""><img src="painel/php/<? echo $exibe["photoescortfour"];?>"></a></li>
       </ul>
       <div class="imgBox"><img  src="painel/php/<? echo $exibe["photoescortthumb"];?>"></div>
          </div>
       <div style="float:left; margin-top:15px; margin-left:15px;"><h2 style="color: white;"><? echo $exibe["anuncio_tit"];?></h2><h5 style="color:grey; line-height: 5px;">Indepedent Escort</h5></div>
   </div>
<script src="https://code.jquery.com/jquery-3.1.1.js"></script>
<script type="text/javascript">
    $(document).ready(function(){
                      $('.thumb a').mouseover(function(e){
                          e.preventDefault();
                          $('.imgBox img').attr("src", $(this).attr("href"))
                      })
                    })


    </script>