Changing the size of the image displayed in a Joomla Article when using the Product Button to add a Add to Cart Button within the article:
edit the file plugins/system/hikashopproductinsert/hikashopproductinsert_view.php
and change the size 100,100 on the line:
echo $this->image->display(@$image->file_path,false,$this->escape(@$image->file_name),
'' , '' , 100, 100);
Change to example 130, 200. You will also have to change the spacing between the Image and the Price or Add to Cart button by going to:
<!-- PRODUCT IMG -->
<div style="height:210px;text-align:center;clear:both;" class="hikashop_product_image">
Change the "height from 100px to 210px or whatever has the better fit for your image size.