Hello
1. To do so you would need to edit the templates index.php file directly (../templates/j51_chloe/index.php). locate the following 2 blocks of code (line 111 - 126) and switch them...
<?php if ($helper->blockExists($this, 'showcase-1')) { ?>
<div id="container_showcase1_modules" class="module_block border_block">
<div class="wrapper960">
<?php $helper->renderBlock($this, 'showcase-1'); ?>
</div>
</div>
<?php } ?>
<?php if ($helper->blockExists($this, 'top-1')) { ?>
<div id="container_top1_modules" class="module_block parallax" style="background-position: 50% 0">
<?php if($particle_block == "top1") {echo $particles;} ?>
<div class="wrapper960">
<?php $helper->renderBlock($this, 'top-1'); ?>
</div>
</div>
<?php }?>
2. What module are you using in the showcase position to display your images?
Ciaran