The Google Reader widget currently uses ClientLogin (this will change in the future).
If you are unable to log into the Google Reader widget in Glimpse, you're probably signed up with Google's 2-step verification.
You would have to create an Application Specific Password which you then have to use for login.
Go to the link below, to Generate new application-specific password:
https://www.google.com/accounts/IssuedAuthSubTokens
