Using the REST API, when you get any sort of user object, they have an avatarURLs property. Unfortunately these URL require the end-user to be logged in, otherwise they see the default blue-and-grey avatar when this avatar is served.
We are using/showing this API info on an internal site that we explicitly do not want users to have to log into Jira to see/use. It would be nice to be able to get to these images without the requestor having to log in.
Maybe this is a setting we can set for permissions in Jira?