Inline images are not showing

[Chesco grow]

I'm drafting a newsletter using the Google Docs Email template.

This Newsletter has inserted inline images from Google Drive that has public view access. 

 I'm further using Gmail mail merge app script to distribute this newsletter so I can give  recipients the options to unsubscribe. I basically used the solution provided here:

Unsubscribe email solution

This code seems robust and it includes options to send the inline image. 

BUT, the inline images don't get sent when using the mail merge. If I send it individually using regular drafted message, the images in the newsletter shows. 

The code is exactly the same as in the link above. 

Please help!