@MangaDoll
I don't think you can go so far.
There are three types of situations:
i. The person thinks only in words.
ii. The person thinks only in pictures.
iii. The person thinks in words and pictures.
Number i is clear: it's where Nakano's mind provides all the visuals and where Nakano makes mistakes.
But ii and iii haven't been perfectly fleshed out. There wasn't a systematic exploration of possibilities by the author or the characters. All of the situations in which we later found out Nakano was wrong, there were factors she couldn't have known, like Yashima's part-time job.
But what can we say of situations for which we never found a mistake, either because the author didn't provide one, or because the idea of "mistake" didn't apply because the images were purely imaginary and not based on fact?
Was the beach holiday delusion totally pictured by Toda, totally pictured by Nakano, or a mixture of both?
The uni student delusion, when re-examined by Nakano afterwards, leads her to the conclusion that "a big part" of what she saw were her own delusions, with Sano's appearance - Toda not knowing he was dating Mana at the time - being proof. But even she didn't say
all of it was.
My point is that the author left this ambiguity on purpose. You don't have to do any mental gymnastics to acknowledge that both of them are perverts. It doesn't have to be "only words" or "only pictures". We haven't had a single example of a character thinking something purely with pictures, though I'd venture that chapter 2, in which Toda only moans in his mind, comes close. But even so, we've never had a situation in which there were picture with no words and later Nakano was proven wrong.
I don't have
proof that Nakano
can see pictures when the other characters are picturing things on their mind. But it's
possible in that nothing in the story has contradicted that notion. The fact that she sees images when they
aren't and these are sometimes wrong doesn't prove she
doesn't when they
are.
The one that comes closest to proof, though it isn't, is when Shimizu hugged her. Nakano
saw Toda's jungle warrior astral project
before she heard his thoughts. Granted, the image
could be a projection by Nakano's mind of her own fear of Toda's reaction on seeing that scene, but she didn't know that he was looking on. So it would have to be a subconscious projection of her fear of his jealousy, which sounds a bit of a stretch. Then again, it's a bit of a stretch that Toda would be picturing himself as a jungle warrior because of his jealousy. So we're left without a solution.
And everyone is free to believe what they want. Which is probably what the author was aiming for.
(Come to think of it, the purple smoke of hatred coming from Toda when Nakano couldn't even see his facial expression or know he was back in the room, might count as an example of mental images without words, which would vindicate my point. But people might argue that one doesn't count for some reason. The name of the chapter is "Consuming grudge".)