Unable to embed to secure sites

I am the Blackboard administrator at Florida Atlantic University. A professor is trying to embed her avatar to Blackboard. I created my own in an attempt to investigate the issue and experienced the same problem. I took it a step further and added the embed code to an html page and loaded the page on to two different servers, one that is secure [https] and one that is not [http]. The avatar loaded from the one that is not secure, but would not load from the one that is.