Connections Docs does not support OLE objects at present and does not render a placeholder image either.
1. For .doc files, there is an invisible placeholder, it occupies the location but you can see nothing.
2. For .docx files, no placeholder. The OLE contents are preserved, but nothing is seen in Docs by the user. When exported, the contents are still there.
This is actually working as designed.
Therefore, this Enhancement Request is for the support of OLE objects as a future feature consideration.
Note: This Enhancement request is similar to: