simple stream object.description does not display

[PowellT]

This is a long shot, but I thought i would try... :)
simple stream add-on example as the following description property for activities
// Optional HTML description of activity. Remove if n/a.
activityInfo.object.description = body.description;

No matter what I do this never works. Hard coding, etc. Nothing.
Might any kind soul have an idea why this does nothing?