The text that you wrote above is inserted into the <head></head> block (you can make the document template a full-fledged html document, with doctype, etc., and insert all the text that you have been given into the head). But it's unreliable. Maybe you remember how we talked for a long, long time when the box stopped using styles from the <head></head> block when uploading a document to pdf :-)
In documents, in my experience, it's better to use inline styles.
Here is an example of how we did it:
<img src="
https://knz.market/{row:product_productimageshort}" height="150px" />