Desglozando su codigo fuente :
Es una imagen y encima mapearon ( etiqueta <map> ) por coordenadas , y el efecto hover con javascript para cada columna
<map id="blocksMap" name="blocksMap">
<area class="blockSelect" href="javascript
:void(0)" shape="rect" coords="211,0,269,229">
<area class="blockSelect" href="javascript
:void(0)" shape="rect" coords="269,0,327,229"><area class="blockSelect" href="javascript
:void(0)" shape="rect" coords="327,0,385,229">
<area class="blockSelect" href="javascript
:void(0)" shape="rect" coords="385,0,443,229">
<area class="blockSelect" href="javascript
:void(0)" shape="rect" coords="443,0,501,229">
<area class="blockSelect" href="javascript
:void(0)" shape="rect" coords="501,0,559,229">
<area class="blockSelect" href="javascript
:void(0)" shape="rect" coords="559,0,617,229">
<area class="blockSelect" href="javascript
:void(0)" shape="rect" coords="617,0,675,229"></map>