There is a feature that allows the ability to add an image to the Forward to a Friend page, seen below. This can only be done by an internal server admin.
- Upload logo image to customer's media library
- Copy image path of that hosted image
- Go to Settings > Support
- Click Edit Account
- Click Settings tab
- Locate "Send to a Friend Logo URL"
- Paste image path
- Click Save
- Send in a Support request with the image path information