By the way, can you count how many circles Mr. kleiber has drawn? Every music teacher tells you that circular motion is the most natural movement you can draw with your body, but it is not the only way to conduct, of course. Try drawing squares and see what kind of sound you get! (okay, it's awkward...) Conducting teachers tell you to move smoothly and gradually like feeling the resistance in water for a legato, bounce at the top of the beats for a staccato, raise or lower your left hand for crescendo and decrescendo... let me tell you, it doesn't matter as long as you can convince the musicians and communicate with them clearly with your gestures. Every conductor is different, just like every pianist is, in their movements, musicality, personalities, relationships to the orchestras ------ every little thing in them affects the SOUND. It is what makes conducting so fun for me. I like to find out what kind of sound I get from interacting with different musicians.
One thing though, Carlos Kleiber always seems to lack eye contact. Maybe I am wrong because I never played for him obviously, but he does seem a little zoomed out. He doesn't correspond his eye contact with his baton and his phrasings. In Mr. Kleiber's conducting, the sound of the full orchestra is shaped simultanously, while some other conductors cue and pick on every little details. So, which conductor lacks eye contact? Check out Karajan, who closes his eyes all the time, even in rehearsals. If you want to see what real eye contact is, check out Fritz Reiner; he stares at you mostly...
This is the best recording I could find of Brahms' fourth symphony ---- I prefer it than the one he did with the Vienna Phil. To some extents it's because of the video. I think music can be seen. That's why we go to performances!