Right now, you could use our ReflectionShader effect for that purpose:
<Rectangle Width="200" Height="200" Fill="Red">
<telerikNavigation:ReflectionShader ElementHeight="200" />
What can be done in the ReflectingContentControl is the synchronization of the ElementHeight and Height of the content.
I will add this control to the suite backlog, hopefully we will have time for implementation in the very near future.
the Telerik team