Life is a mystery

I think it was about the angle of his elbow.

https://www.youtube.com/watch?v=EFa-hVu3_TY&t=95

The Price Is Right with Bob Barker FULL EPISODE September 13, 1982 | 9/13/82 | #4581D

YouTube
It does kinda makes sense ergonomically. You prevent your arm from being in a raised position for a long time, and it’s more relaxed as you hold it lower.