Because it makes them seem powerful. In Western culture, we read from left to right, and we watch theater and television that way, too. Our eyes end up on the right side of the screen—where the host sits. In the theory of stagecraft, it's understood that a rightward placement telegraphs royalty. So no matter how famous the guest may be, sitting to the left makes him or her seem subservient.

　　因为这让他们看上去更有威势。西方文化中，人们的阅读方式是从左到右，看戏和看电视也是这样。我们的眼睛最终停留在屏幕的右边——主持人所在之处。舞台艺术理论表明，右边的位置能彰显庄严。所以不管嘉宾是多显赫的人物，左边的位子都让他/她显得卑微。

　　Stage designers hold that guests make a stronger impression if they enter from stage left, crossing in front of the host and shifting the audience's focus ever so briefly.

　　舞美师认为如果嘉宾从舞台左侧进入时会给观众带来更深刻的印象。嘉宾随后穿过镜头，从主持人面前走过，只会稍微转移一下观众的注意力。