Summary

Comment avatars do not render in Customer Portal for users that are JIRA Users (this includes Agents as well as Customers that are also JIRA Users), or non JIRA User Customers that have added a custom avatar.

Steps to Reproduce

1. Install JIRA. In my test instance, I installed JIRA 6.4.10
2. Install JIRA Service Desk 2.5.4. In my test, I used an ABP license.
3. Have a Service Desk created. In my test, I used the "My First Service Desk" that installed automatically.
4. Add a comment to an existing Issue. You can add as many comments as you desire.
5. Open the Issue in the Customer Portal.
6. The avatar does not render.

Non JIRA User customer avatars do not render as well, if they have customized them. If they use the default avatar, it will render.

1. Have a customer invited to the Service Desk
2. Once the customer changes their default avatar, it will also fail to render.

Expected Results

All avatars in the commentary area of the Customer Portal would render.

Actual Results

See Screenshots. The avatars do not render, but instead have broken image icons.