I went and looked at the source of the page and it seems like there is a big opening for something involving Mewtwo.
<div id="info1">
<a href="../img/pokemon/long/info/infoGenoR.png" class="geno" rel="0" target="_blank"><img src="../img/pokemon/long/genoR.gif" width="387" height="368"></a>
<a href="../img/pokemon/long/info/infoM2.png" class="m2" rel="1" target="_blank"><img src="../img/pokemon/long/m2.gif" width="420" height="386"></a>
</div>
<div id="info2">
<a href="../img/pokemon/long/info/infoGeno.png" class="genoY" rel="2" target="_blank"><img src="../img/pokemon/long/genoY.gif" width="98" height="125"></a>
<a href="../img/pokemon/long/info/infoGeno.png" class="genoB" rel="2" target="_blank"><img src="../img/pokemon/long/genoB.gif" width="122" height="136"></a>
<a href="../img/pokemon/long/info/infoGeno.png" class="genoF" rel="2" target="_blank"><img src="../img/pokemon/long/genoF.gif" width="106" height="127"></a>
<a href="../img/pokemon/long/info/infoGeno.png" class="genoA" rel="2" target="_blank"><img src="../img/pokemon/long/genoA.gif" width="115" height="122"></a>
</div>
info2 is where the smaller Genesects are stored. All they have to do is add an extra line for a Mewtwo form (or his son?) and it's there.
