When testing complications from a watch face, the call to exitTo() launches the publisher in Glance mode when it needs to launch it in App mode, showing the full app, just as it does on the real device.
The workaround is to select Settings->Glance Launch Mode to Launch in Normal Mode. For multi complication and multi view apps this is a must so that the app can display the correct view.
This may seem like a minor issue given the work around, but I'd expect the Sim to work like the real device to save dev time. We shouldn't need to manually switch back and forth depending on which we are testing, the watch face vs the app/widget/glance.