There's nothing true or false; only thinking makes it so

Filmmaker Errol Morris argues that truth and falsity are concepts that can't be applied to pictures, only to statements about pictures. I'm not sure what to make of this argument; by his logic, it seems to me, truth are falsity are concepts that can't be applied to words, only to statements about words. Meanings only exist in context, sure. But what do we learn from that? How should I think about pictures differently because of that?