"Simple alternate eye rendering" SDK sample , why is alternate eye rendering producing double images

We caught this in regards to the recent mod for GTA V, which is using "alternate eye rendering".

Essentially, alternate eye rendering (as I understand it) is splitting rendering "in half", so that each eye sees 45hz, l-r-l-r-l-r and so forth rather than 90hz. Check. But what we found is that in the mod but also in the "simple alternate eye rendering" demo from the Win SDK demo, there is a "double" image in each eye. It also states so on the source code of the demo.

What are we seeing we here, and why does alternate eye rendering produce a ghost/double image? It is like that the Oculus software (possibly the timewarp part) is interpolating the 45 frames into 90hz. Is this intended?

Ty!