This one and Mobile device redirection are two independent web parts.
In case you still haven't figured out the functionality of Switch Mobile Device Detection, a quick look into its code should reveal it (~\CMSWebParts\DeviceProfile\SwitchDeviceDetection.ascx.cs):
The result is a cookie set:
CookieHelper.SetValue(CookieName.ShowDesktopVersion, value.ToString(), DateTime.Now.AddYears(1));
and a redirect performed:
The cookie is then used only in DeviceProfileInfoProvider method GetCurrentDeviceProfiles to decide whether to load the profile from cookie or not.
Please feel free to contact us if you have any additional questions.