Lots of descriptions there of what other people do with their hands or arms, but none of them matching what I'm describing: no, it's not "Norma arms", X-factor or dancing with the hands, solfa pitching or any other such ruse. Mooh has it right: it IS an affectation. I'm not advocating strait-jackets either, pfr!
Just let the hands relax by the sides for most of the time, maybe some movement to emphasise an important note or phrase, but please stop this constant pulsating up and down of one hand throughout every note of the song: might just as well put a baton in it and be done with it!
(And also let's stop the pointless microphone fiddling while I'm having a moan!)
Another reason to look away, Leeneia!