Was Fritz more like Karajan? I don’t know anything about him, but I find your comment fascinating.
I’d put it this way, brefly: Reiner communicated as much with his stony hawklike stare as with his baton.
His friend and mentor Richard Strauss had a similar seemingly economical style, at least in old age.
I never saw Reiner conduct in person, but a colleague I met many years later did. He confirmed the legend that the man had a “postage stamp” movement at the tip of his baton.
However, various videos on Youtube show that this claim was exaggerated.