Did you try the Email Templates? 

If you check the Email Connector module it lets you send emails with templates.

Now important thing is, This email template is configurable in a RICH Text editor which lets to make very nice HTML email contents.

So lets assume you have an entity which contains the image URL of the item in an attribute that you are ordering, you can pass this entity object as the parameter to the Email Sending JavaAction provided by the EmailConnect module also pass the template object too.

In the template you can add an image tag and its src should be set with the Entity that you prepared above.

hope you got the idea :)