How does DAM Parse Word Documents create renditions/modify asset properties?

I've uploaded 2 word documents (both .docx) on my local and Adobe AMS-hosted AEM. Both documents contains a form.

In both instances, these things happened:

1. DAM Parse Word Documents workflow triggered

2. images presents on the Word document where identified as sub-assets

But something is different from the documents. When inspecting the properties for both documents:

- document1 has "Referenced by: Page extract from Word"

- document2 has no "Referenced by: Page extract from Word"

According to this page (https://helpx.adobe.com/au/experience-manager/6-4/assets/using/managing-assets-touch-ui.html#main-pars_title_20), a cq:Page node is created for the documents and that is correct. I found these:

- http://localhost:4502/content/dam/mytest/document1.docx/jcr%3acontent/renditions/page.html

- http://localhost:4502/content/dam/mytest/document2.docx/jcr%3acontent/renditions/page.html

Any ideas what's happening in relation to "Referenced by: Page extract from Word"? I would've expected both to have it or not have it.

Thanks