Mac Word 2019 does not display MHTML images

I have a DOCX with a MHTML file with embedded image included in an altChunk element. The DOCX or MHTML itself is displayed in MS Word 2019 on Windows. However, MS Word 2019 for Mac shows text only, but not the images. Is it a Mac Word bug? E.g. see the attached DOCX file.

Note: see also https://github.com/evidenceprime/html-docx-js/issues/129

Update: I've tried to create a text with an image in Mac Word, save as MHTML file. Close Word. Open Word and open the MHTML file - images are not visible, too. So, it's a Mac Word bug. 

Workaround: inline images using data: URI, i.e.

<img src="data&colon;image/png;base64,..."> 

However, the Word for Mac treats alpha channels as black in such inline images - another bug, so the image should not have alpha channel.