For me, the saddest part during the performance was when he turned to the crowd and smiled.
I know what you mean, it's kindof in a "Look ma" approval seeking look. Cool find, thanks for posting. I certainly think it's more sad in a 'depressing yo see what became of him' kind of way. There's really nothing tearjerking about the performance of the song, it's pretty bad. Other than it shows how far Elvis had fallen from grace.