Regardless of the brevity of the stop and detached professionalism of the Royal Guard, Twilight felt violated as the train continued its journey onward—personal student of the Princess or not, Twilight had to submit to the same scrutiny as anypony else who traveled into Canterlot by rail these days.  Her resentment was offset by the memory of dozens of doppelganger Twilights confronting Rainbow Dash; the Guard certainly had reason to believe that even a familiar face could be a changeling.