CompositeTransform3D in Windows 10

I believe this has been mentioned in several blog posts (such as this one), but I missed one important part, and it took me almost an hour to figure out why my CompositeTransform3D does not give a nice 3D effect but only a “scaling” effect.

Turn out I need to have to put a PerspectiveTransform3D in the container of the element with CompositeTransform3D.