 To see why, let’s focus on one theory of propositions that purports to address Frege cases (a similar point could be made on any other such theory). Imagine that propositions are Russellian, but are believed under guises. So I might believe de re of someone that their pants are on fire, and also see on a Zoom call that someone’s pants are on fire. If the person about whom I have the de re belief is also the unfortunate Zooming individual, then I believe the same proposition under two guises—one de re and one descriptive (with the relevant description being something like the guy on Zoom).