erpnext/templates/includes/macros.html

{% macro product_image_square(website_image, css_class="") %}
{% if website_image -%}
	<meta itemprop="image" content="{{ frappe.utils.quoted(website_image) | abs_url }}"></meta>
{%- endif %}
<div class="product-image product-image-square
	{% if not website_image -%} missing-image {%- endif %} {{ css_class }}"
	{% if website_image -%}
	style="background-image: url('{{ frappe.utils.quoted(website_image) | abs_url }}');"
	{%- endif %}>
</div>
{% endmacro %}

{% macro product_image(website_image, css_class="") %}
    <div class="product-image {% if not website_image -%} missing-image {%- endif %} {{ css_class }}">
    	{% if website_image -%}
    		<img itemprop="image" src="{{ frappe.utils.quoted(website_image) | abs_url }}" class="img-responsive">
    	{%- endif %}
    </div>
{% endmacro %}