I find it interesting in how there is some dependence on the fingerprint secret being shared across the Telegram channel in order to verify identity. What if a

I find it interesting in how there is some dependence on the fingerprint secret being shared across the Telegram channel in order to verify identity. What if a user sends the screenshots of the fingerprint over, say, a medium decided in the chat on the fly? Unless you can MITM every service they're using, you could just /tweet/ the fingerprints, for instance, and check on a different machine for a matching key. Or what if the screenshot is tampered with by hand, like, signing the center of the square with a finger drawn, transparent signature? How would an attacker replicate that? Of course, the "supervillain" model still works and enough computation time and power might find it, but there are a multitude of ways to ensure that the secrets match on everyone's devices.