Comment 2 for bug 1532974

unity8.log supports the above:
qtmir.applications: TaskController::isApplicationPid - appId= "ubuntu-system-settings" pid= 31176
ApplicationManager REJECTED connection from app with pid 31176 as it was not launched by upstart, and no desktop_file_hint is specified
qtmir.mir: MirWindowManagerImpl::add_surface(): size requested ( 400 , 720 ) and placed ( 1920 , 1080 )
qtmir.mir: SessionListener::surface_created - this= SessionListener(0x7f4b40155390) session= 0x7f4b2800b860 surface= 0x7f4b2800bdb0
qtmir.applications: ApplicationManager::onSessionCreatedSurface - sessionName= QtUbuntu
qtmir.surfaces: MirSurfaceManager::onSessionCreatedSurface - mirSession= 0x7f4b2800b860 surface= 0x7f4b2800bdb0 surface.name=
qtmir.sessions: Session::resgisterSurface - session= "QtUbuntu" surface= qtmir::MirSurface(0x2fec900)
qtmir.sessions: Session::appendSurface - session= "QtUbuntu" surface= qtmir::MirSurface(0x2fec900)
qtmir.surfaces: MirSurfaceItem::setSurface surface=qtmir::MirSurface(0x2fec900)
qtmir.surfaces: MirSurface[0x2fec900,"ubuntu-system-settings"]::registerView(50557120) after=1
qtmir.surfaces: MirSurface[0x2fec900,"ubuntu-system-settings"]::setFocus(false)
qtmir.surfaces: MirSurfaceItem::setSurface surface=qtmir::MirSurface(0x2fec900)
qtmir.surfaces: MirSurface[0x2fec900,"ubuntu-system-settings"]::registerView(47755280) after=2
qtmir.surfaces: MirSurface[0x2fec900,"ubuntu-system-settings"]::resize old (1920,1080), new (634,498)
qtmir.surfaces: MirSurface[0x2fec900,"ubuntu-system-settings"]::setFocus(true)

See how the window goes from requested 1920x1080 back to 634x498 after having requested 400x720.