When using Algolia For Shopify to index your Shopify articles data, the body_html and body_html_safe attributes contain the description data from your Shopify article.
The body_htmlattribute takes your description data, including HTML, and truncates the value to 2000 characters.
The body_html_safe attribute takes this already-truncated body_html value and removes the HTML, so if there is any HTML in body_html, the value of body_html_safe will inherently be shorter.