Oh no I just had another bad idea for Picard.
What if Commodore Oh wears sunglasses bc she’s from the Mirror Universe (Lorca weak-eyes bc of altverse was dumb but I wouldn’t put it past them to pull that shit twice), we don’t know what’s happened there in the intervening 20+ years either….
I just assume she is a Romulan masquerading as a Vulcan. Probably an old Tal Shiar deep cover agent like Ambassador T’Pel who had infiltrated the Diplomatic corps for possibly decades. Only someone very familiar with Vulcan biology would make the connection, and Vulcans are known for their transparency and openness about their biology.
That was my initial thought as well, but as far as we know, Romulans do not have the Vulcan telepathic skills. I don’t think off the top of my head we’ve ever seen a Romulan attempt a mind meld.
Vulcans and Romulans over the couple of millennia since their separation have become different enough species that one can’t donate blood to the other.
Then, and my memory of this ep is sketchy, Enterprise had Romulans stealing Andorian Aenar specifically because of their telepathic skills (and pilot the telepresence drone), which I think stated outright Romulans didn’t have that skill?
Of course, canon in Star Trek is mutable, and PIC could choose to ignore all that too.