Mind Map elements alternate images

[Tree]

Why are the options "select alternate image" and "apply image from clipboard" grayed out for topic elements on a mindmap diagram?  

[KP]

MindMap elements are stereotyped UML elements drawn by a shape script. It isn't currently possible to apply an alternate image to an element with a shape script.

[Tree]

Thank you.  I was trying to use a very basic element type that supported composition to provide hierarchical process guidelines.  I am attempting to use EA to include process within the model to make it easier for the engineers etc. Are there any other modeling elements that are as clean and simple as mind maps that support composites?