The photos and videos (media in general) attachment require a server & host to bee uploaded & link to the product. This couldn't be done in your email client.
If you could come across any service that has this feature available, please let us know so we could try to learn from them.
Lily Vuong
I cannot get any of the email templates to include the ability to insert a picture to the email review. I have enabled it in the settings as well.