This requires basic knowledge of CSS. If you're OK with that, simply edit the 2 template overrides in K2 (item.php and category_item.php) after you copy them inside your template structure. When you edit them, just locate the relevant code and move it as you like.
If you want to print an icon if a video exists, just use this PHP code:
<?php if(!empty($this->item->video)): ?>
<i>Some icon here</i>
<?php endif; ?>
Learn how to copy the source K2 template overrides to your Joomla template here:
getk2.org/documentation/tutorials/174-templating-with-k2-and-the-concepts-of-sub-templates 
