With a little bit of HTML / CSS you can accomplish this. You will likely want to set a default max-width in the plugin settings or you can use the width attribute to the shortcode to limit the viewer width on specific embeds - I mention it just for future reference in case you want to set other documents at wider or narrower dimensions than your preset default (https://wp-pdf.com/premium-instructions/shortcodes/).
Create a new CSS class with the following rules (you may want to add other margins to suit your theme):
.left { float: left; margin-right: 10px; /* set a right margin to push the wrapped text off the viewer box */ }
Then in the page / post content using the Text (HTML) tab, wrap the embedder shortcode in a div with the new class:
<div class="left"> [pdf embedder shortcode] </div>
The end result: